[Federal Register Volume 62, Number 172 (Friday, September 5, 1997)]
[Rules and Regulations]
[Pages 46907-46919]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-23318]
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DEPARTMENT OF TRANSPORTATION
National Highway Traffic Safety Administration
49 CFR Part 571
[Docket No. 85-6; Notice 12]
RIN 2127-AG05
Federal Motor Vehicle Safety Standards; Hydraulic Brake Systems;
Passenger Car Brake Systems
AGENCY: National Highway Traffic Safety Administration (NHTSA),
Department of Transportation.
ACTION: Final rule.
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SUMMARY: This document amends Federal Motor Vehicle Safety Standards
Nos. 105 Hydraulic Brake Systems and 135 Passenger Car Brake Systems to
accommodate the brake systems on electric vehicles. The amendments
address unique characteristics of brake systems on electric vehicles,
such as regenerative braking, and are intended to assure safe
performance for those brake systems. The amendments of Standard No. 105
apply to electric trucks, buses, and multipurpose passenger vehicles.
They also apply to electric passenger cars that have not availed
themselves of the option of conforming to Standard No. 135, which is
mandatory for all passenger cars manufactured on and after September 1,
2000. The amendments to Standard No. 135 complement those made to
Standard No. 105.
DATES: The amendments to both standards are effective October 20, 1997.
Compliance with Standard No. 105 is mandatory as of September 1, 1998.
Compliance with Standard No. 135 is mandatory as of September 1,
2000, the effective date of Standard No. 135. Petitions for
reconsideration of the final rule must be submitted not later than
October 20, 1997.
ADDRESS: Petitions for reconsideration should be addressed to Docket
85-6; Notice 12, and submitted to Docket Room, NHTSA, Room 5108, 400
Seventh St. SW, Washington, DC 20590.
FOR FURTHER INFORMATION CONTACT: Samuel Daniel, Vehicle Dynamics
Division, Office of Vehicle Safety Standards, NHTSA (Phone: 202-366-
4921).
SUPPLEMENTARY INFORMATION:
Table of Contents
1. Background
2. Issues relating to Definitions
3. Partial failure (Standard No. 105)
4. Issues relating to RBS:
A. RBS as part of the service brake system
B. RBS braking effects
C. ABS control over RBS
5. Issues relating to warning indicators:
A. Red ``BRAKE'' lamp as signal of RBS failure
B. Common ABS/RBS malfunction warning indicator
6. Issues related to compliance testing:
A. Procedure for determining battery state of charge
B. Procedure for charging batteries during burnish
C. Procedure for recharging batteries
D. Testing in gear as opposed to testing in neutral
E. Testing at low state of charge
7. Issues relating to test conditions:
A. Initial brake temperature (IBT)
B. Static parking brake test
C. Stops with engine off (Standard No. 135)
8. International harmonization
Effective dates
Regulatory analyses:
[[Page 46908]]
Executive Order 12866 (Regulatory Planning and Review) and DOT
Regulatory Policies and Procedures
Regulatory Flexibility Act
Executive Order 12612 (Federalism)
National Environmental Policy Act
Executive Order 12778 (Civil Justice Reform)
1. Background
On January 15, 1993, NHTSA published a Supplemental Notice of
Proposed Rulemaking (SNPRM) concerning brake system performance of
electric vehicles (EVs) (Docket No. 85-6; Notice 7, 58 FR 4649). Notice
7 proposed amendments to Standard No. 105, Hydraulic Brake Systems and
revised portions of a proposed Standard No. 135, Passenger Car Brake
Systems. Standard No. 135 was issued as a final rule (Notice 8, 60 FR
6411) on February 2, 1995, with an effective date of March 6, 1995.
Passenger cars, including EVs, may comply with either Standard No. 105
or Standard No. 135, until September 1, 2000, after which Standard No.
135 will become the sole Federal motor vehicle safety standard for
passenger car brakes. Standard No. 105, as amended in this notice, will
continue to apply to electrically-powered multipurpose vehicles,
trucks, and buses after September 1, 2000, although NHTSA has proposed
(Notice 11) that Standard No. 135 be amended to apply, effective
September 1, 2002, to multipurpose passenger vehicles, trucks, and
buses with a GVWR of 10,000 pounds or less (61 FR 19602).
On September 26, 1995, the agency published a Further Supplemental
Notice of Proposed Rulemaking (FSNPRM), Notice 10 (60 FR 49544). Notice
10 refined Notice 7's proposed amendments to Standard Nos. 105,
Hydraulic Brake Systems, and No. 135, Passenger Car Brake Systems. For
a detailed history of the development of Federal braking standards for
EVs, the reader may consult Notice 7 and Notice 10.
Seven commenters, all motor vehicle manufacturers, responded to
Notice 10. They were Toyota Motor Corporation, General Motors
Corporation (GM), Chrysler Corporation, Ford Motor Company, Nissan
North America, Hydro Quebec (HQ), and Honda. All supported the agency's
rulemaking for EV brake systems. Notice 10 solicited specific comment
on two general questions: (1) Whether 2 miles is sufficient distance
for an EV to attain its maximum speed for compliance test purposes, and
(2) whether any EV manufacturer plans to equip its vehicles with a
braking system that includes a regenerative braking system (RBS) that
does not include an anti-lock braking system (ABS). All seven
commenters indicated that 2 miles was sufficient for an EV to obtain
maximum speed under most conditions. None of the commenters indicated
that they planned to produce EV brake systems that included RBS but
excluded ABS.
The following were the specific issues raised by comments to Notice
10.
2. Issues Relating to Definitions
Notice 10 proposed revising the existing definitions of ``Backup
system'' and ``Split service brake system'', and adding definitions for
``Electric vehicle or EV'', and ``Regenerative braking system or RBS.''
These would apply to both Standards Nos. 105 and 135. With the minor
addition noted below for RBS, the four definitions have been adopted as
proposed.
In addition, Notice 10 proposed a definition of ``Maximum speed or
Vmax'' for Standard No. 135. Standard No. 135 now contains a definition
of the term, thus, this Notice only adds language to the definition
that is appropriate for EVs. With reference to RBS, HQ suggested that
the term ``dynamic braking'' be adopted for purposes of Standards Nos.
105 and 135. Dynamic braking includes vehicle retardation that results
from dissipation of electrical energy when the battery(s) is at a high
state of charge as well as the retardation that occurs during battery
recharging when the battery(s) state of charge is low. HQ suggested
that the RBS definition proposed in Notice 10 be modified to include
reference to the dissipation of the energy generated by the propulsion
motors. The proposed definition stated that the energy produced by the
propulsion motors in the regenerative mode is returned to the
battery(s). Dissipation of the electrical energy developed through the
RBS could develop braking forces that are not dependent on the state-
of-charge of the batteries, according to HQ.
NHTSA agrees with HQ's observations that dissipation of the energy
produced by RBS while the propulsion motor(s) are in the regenerative
mode was not addressed in the proposed RBS definition. Since RBS
control systems with the capability of dissipating energy generated by
the RBS are under development, the agency believes that the definition
of RBS should include a reference to this capability. Thus, NHTSA is
amending the definition proposed in Notice 10 for regenerative braking
system (RBS) in Standards Nos. 105 and 135 to state that it ``* * *
means a system for recovering or dissipating kinetic energy. * * *''
However, the agency does not believe a definition for ``dynamic
braking'' should be added to the braking standards. HQ did not indicate
how it would be placed at a disadvantage without the new definition.
The definition for dynamic braking recommended by HQ involves a
combination of the energy dissipated and stored by the RBS control
system. The agency feels that inclusion of the energy dissipation
feature in the definition for RBS is sufficient to address HQ's
comment.
Nissan commented on the lack of definition of electrically-actuated
service brakes'', and asked that the agency adopt one to specify
electrically-actuated service brake system components. Toyota
recommended that the agency define the term as ``a braking system which
converts the electric energy of the battery directly to the braking
force.'' In its view, it is necessary to distinguish systems whose main
braking power is electrical from those systems in which electric energy
is used to operate power assist units such as vacuum and hydraulic
pumps. Electrically-operated power assist units should not be
considered electrically-actuated service brakes. Honda also asked for a
clarification of the term.
Notice 10 uses the term ``electrically-actuated service brakes''
several times in the prospective regulatory text for Standards Nos. 105
and 135, and, as the commenters noted, without proposing a definition
for it. One example of use of the term is in proposed paragraphs
S5.1.3.5 and S7.11.3 of Standards Nos. 105 and 135 respectively, called
Electric brakes, which specify partial failure performance requirements
for vehicles with any single failure in the electrically-actuated
service brakes.
NHTSA believes that Notice 10 contained an adequate explanation of
electrically-actuated service brakes, brake power assist units, and
electric or electronic transmission or service brake control.
Electrically-driven brake power assist units, such as hydraulic pumps
or vacuum motors that serve to reduce the driver-applied brake control
force, are not electrically-actuated service brake components. Neither
are systems in which the brake control signal is transmitted
electrically or electronically from the brake control to the foundation
brake (commonly known as electronic braking systems). The definition of
``electrically-actuated service brakes'' will read: ``Electrically-
actuated service brakes means service brakes that utilize electrical
energy to actuate the foundation brakes.''
HQ requested that the definition of ``antilock brake system'' (ABS)
in Standards No. 105 and 135 be modified to indicate that ABS is a
capability of the service brake system. ABS is defined
[[Page 46909]]
in the standards as part of the service brake system rather than a
capability of the service brake system. HQ also suggested that the
definition of ``ABS'' be changed by substituting the term ``braking''
for ``brake actuating'' because the latter implies the actuation of a
foundation brake. According to HQ, the term ``braking'' would apply to
any type of braking force modulation including braking forces generated
by vehicle components other than the foundation brakes.
The agency does not concur with these suggested modifications to
the definition for ``ABS''. It believes that the braking forces
developed by an electric motor(s) in an EV are covered adequately in
the definition of ``regenerative braking system.'' Also, most
conventional braking systems need to have specific hardware added to
accomplish the ABS function. The agency has concluded that the current
definition of RBS adequately addresses the braking system design
features described by HQ.
3. Partial Failure (Standard No. 105)
Notice 10 proposed adding partial failure provisions to Standard
No. 105 in a new paragraph S5.1.2.3., that a vehicle ``shall be capable
of stopping from 60 mph within the corresponding distance specified in
Column IV of Table II when there is a single failure in an electric
brake circuit, and with all other systems intact.'' This was supported
and has been adopted.
In addition, new wording was proposed under the partial failure
requirements to address failures of an RBS that is part of the service
brake system, since the RBS is not a separate ``circuit'' of the
service brake system. This, too, was supported and has been adopted.
4. Issues Relating to RBS
A. RBS as Part of the Service Brake System
Notice 10 proposed that RBS would be ``considered to be part of the
service brake system if it is automatically activated by an application
of the service brake control, if there is no means provided for the
driver to disconnect or otherwise deactivate it, and if the vehicle has
no `neutral' transmission position.''
GM indicated that the existence of a neutral transmission position
should not exclude RBS from being considered part of the service brake
system, according to GM, because a neutral transmission position need
not have any effect on the operation of an RBS. The ability of the
driver to disengage the RBS should be the only factor that precludes an
RBS from being considered part of the service brake system.
Toyota commented that to its knowledge, almost all EVs with RBS
have a neutral transmission position, and that the ``no neutral
transmission position'' criterion should be deleted from conditions
required for an RBS to be considered part of the service brake system.
Honda believed that the conditions under which RBS is considered
part of the service brake system should be modified to indicate that
the vehicle transmission may have no electrical or mechanical neutral
position. Honda is concerned that RBS may be designed such that any
torque from it is canceled when the shift lever is placed in neutral,
even though there is no mechanical disconnection between the drive
train and the motor.
NHTSA agrees with GM and Toyota that the lack of a neutral
transmission position need not be a condition for inclusion of RBS in
the service brake system, and is deleting it from the final rule. A
neutral transmission position need not have an effect on RBS because
the neutral position does not require that the drive line be
mechanically disconnected from the propulsion motor(s), as indicated by
Honda.
Honda requested that a distinction be made between a neutral
position that includes mechanical disconnection between the propulsion
battery(s) and the drive line and one that does not. NHTSA does not
believe that a definition for ``neutral'', as requested by Honda, is
needed. However, Notice 10 proposed that including RBS in the service
brake system requires that the selected position of the vehicle's
transmission have no effect on the RBS function.
NHTSA believes that RBS should operate in the same manner and under
the same conditions as the service brake system if it is to be included
as part of the service brake system. For example, the service brake
system is controlled by the service brake control only. If RBS is to be
included in the service brake system, it should also be controlled by
the service brake control only. Similarly, the service brake system is
operational in all transmission positions (gears) and RBS should also
be operational in all transmission gears, including neutral, if it is
to be considered part of the service brake system.
In view of the comments to Notice 10, NHTSA is modifying the
conditions under which RBS is considered part of the service brake
system. Accordingly, the final rule amending Standards No. 105
(S6.2.4(a)) and No. 135 (S5.1.3(a)) states that ``the RBS is considered
part of the service brake system if it is automatically activated by an
application of the service brake control, if there is no means provided
for the driver to disconnect or otherwise deactivate it, and it is
activated in all transmission positions, including neutral.''
B. RBS Braking Effects
Nissan believes the retardation capacity of some electric
propulsion motor(s) is insufficient to be characterized as braking.
Nissan requests that only RBS that demonstrate braking effects greater
than the transmission braking effects required in Standard No. 102,
Transmission shift lever sequence, starter interlock, and transmission
braking effect, be considered in Standards Nos. 105 and 135.
NHTSA does not believe RBS systems should be required to have at
least a two speed transmission, as would be required if the
transmission braking effects provisions of Standard No. 102 were added
to the braking standards. It is practical for an EV to perform with a
single gear ratio transmission. The agency believes that the Nissan
request would limit EV design unnecessarily. Therefore, it is taking no
action on this request.
C. ABS Control Over RBS
Proposed Paragraphs S5.5 of Standard No. 105 and S5.1.3 of Standard
No. 135 state that ``* * * for an EV that is equipped with both ABS and
RBS that is part of the service brake system, the ABS must control the
RBS''.
Chrysler cautioned that EV technology is still new and
manufacturers need more design flexibility in this area, and argued
that it is inappropriate for the agency to require that RBS be
controlled by ABS and that the agency should specify performance
requirements.
The purpose of the proposed requirement is to assure that RBS is
not operating while ABS is reducing the braking forces in the
foundation brake system. The added braking torque of the RBS under this
condition would be counter-productive and may cause vehicle
instability. NHTSA believes that the requirement is necessary for RBS
that is part of the service brake system since these systems cannot be
controlled by the driver. The requirement is adopted as proposed.
[[Page 46910]]
5. Issues Relating to Failure Indicators
A. Red ``BRAKE'' Warning Lamp as Signal of RBS Failure
Notice 10 proposed new paragraphs in Standards No. 105 (S5.3.1) and
No. 135 (S5.5.5) which would require that a red ``brake'' indicator
lamp be illuminated under various conditions including the three
following: ``(e) For a vehicle with electrically-actuated service
brakes, failure of the source of power to the brakes, or diminution of
the state of charge of the batteries to a level less than that
specified by the manufacturer for the purpose of warning a driver of
degraded brake performance, (f) For a vehicle with electric
transmission of the service brake control signal, failure of the brake
control circuit, and (g) For an EV with RBS that is part of the service
brake system, failure of the RBS.''
GM commented that failure of the RBS in all known EV brake systems
will not cause a significant reduction in overall braking performance.
Therefore, failure of the RBS should not result in the illumination of
a red telltale lamp since red telltales are used to indicate emergency
situations in which the vehicle needs immediate service. An amber
driver warning display such as the ABS telltale should be allowed in
the standards as an option to indicate an RBS failure whether or not
RBS is part of the service brake system.
According to Ford, failure of RBS will diminish an enhancement of
the braking system but will not result in substantially reduced braking
performance. The RBS on-board telltale need not be red, indicating the
need for immediate service, but an amber lamp, such as the ABS warning
indicator, should be an option.
According to GM and Ford, the foundation brake system on their EV
models is capable of meeting all braking performance requirements
without contribution from the RBS. As a result, GM and Ford believe
that a failure of the RBS system should not require the illumination of
a red ``Brake'' indicator.
Honda believes that manufacturers should be allowed to use an amber
indicator lamp instead of a red lamp when a failure occurs in the brake
control circuit of a vehicle with electric transmission of the service
brake control signal provided that the total braking force is not
impaired by the failure. It, too, agrees that, in the event of RBS
failure or failure of the electrical circuitry that controls the
hydraulic brake force, all braking would be done by the hydraulic
system with no loss of performance.
Honda further states that Standards Nos. 105 and 135 do not require
illumination of a red brake warning lamp when a brake power unit, power
assist unit, or an ABS failure occurs.
In Notice 10, the agency retained the proposed requirement for
illumination of an on-board, red ``Brake'' lamp to indicate failure of
these systems. Notice 10 proposed that the requirement for a red brake
lamp for RBS failures be limited to cases in which RBS is part of the
service brake system. This was a modification of Notice 7, which
required that failure of RBS systems that are part of the service brake
system and those that are not, be indicated by a red on-board brake
lamp.
The arguments made by commenters to Notice 10 stating that braking
performance is not substantially diminished by a failure of the RBS are
convincing. If RBS is part of the service brake system, it is active at
all times and is controlled by application of the service brake only.
The contribution of RBS to overall vehicle braking may be substantial
at times and this contribution is dependent on many factors including
the state of charge of the propulsion battery(s). NHTSA agrees with the
commenters that a failure of RBS will not affect the ability of the
foundation brakes to provide adequate brake performance under most
conditions. The agency also agrees with commenters that the loss of the
RBS braking contribution will not result in a safety hazard in an
emergency stop situation. The agency accepts the request by GM, Ford
and Honda to allow an optional amber (yellow) lamp to warn drivers of a
failed RBS system. NHTSA believes that illumination of the red
``brake'' warning signal would signify the need for immediate remedial
action by the driver, which is not warranted. The ``service soon''
message that is conveyed by an amber on-board telltale is sufficient
warning in the case of a failed RBS system that is part of the service
brake system.
NHTSA has not granted Honda's request that an amber lamp be allowed
which would indicate a failure in the electric brake control circuitry
of a brake system in which the brake control signal is transmitted
electrically from the service brake control to the foundation brakes
(paragraph S5.3.1(f) of Standard No. 105, and paragraph S5.5.1(f) of
Standard No. 135). The final rule allows the option of illuminating an
amber on-board lamp in the event of an RBS failure for cases in which
the RBS is part of the service brake system. However, an amber
indicator lamp will not be allowed as an option to replace a red
indicator to signal failure of the control circuit for vehicles with
electric transmission of the brake control signal. See the amended text
in the discussion under the heading that follows.
B. Common ABS/RBS Malfunction Indicator
Ford requests that the option be provided to group the RBS and ABS
malfunction modes with a common warning indicator because the two
systems share many of the same software and hardware components.
NHTSA agrees that a common ABS/RBS malfunction warning indicator
should be allowed for cases in which the RBS is part of the service
brake system. In these cases, ABS and RBS are required to communicate
(see proposed paragraph S5.5 of Standard No. 105) and are likely to
share many components, as indicated by Ford. Accordingly, paragraph
S5.3.1(g) of Standard No. 105, and paragraph S5.5.1(g) of Standard No.
135 are adopted to require an indicator to indicate failure of the RBS
and optional illumination under other circumstances: ``(g) For an EV
with RBS that is part of the service brake system, failure of the RBS.
An amber lamp may be used displaying the symbol `RBS'. RBS failure in a
system that is part of the service brake system may also be indicated
by an amber lamp that also indicates ABS failure and displays the
symbol `ABS/RBS'''.
6. Issues Related to Compliance Testing
A. Procedure for Determining Battery State of Charge
NHTSA proposed that the state of charge of the propulsion batteries
be determined in accordance with SAE J227a Electric Vehicle Test
Procedure, February 1976 (S6.2.1 of FMVSS No. 105, S6.3.11.1 of
Standard No. 135), specifically that the applicable sections of J227a
are 3.2.1 through 3.2.4, 3.3.1 through 3.3.2.2, 3.4.1 and 3.4.2, 4.2.1,
5.2, 5.2.1, and 5.3. There were no comments on this issue and the
proposal has been adopted.
B. Procedure for Recharging Batteries During Burnish
The burnish procedures (S7.4 of Standard No. 105 and S7.1 of
Standard No. 135) result in a maximum distance between each of the
burnish stops of 1.24 miles. The continuous acceleration and
deceleration of a burnish procedure could result in fairly extensive
battery depletion after approximately 40 stops. Therefore, NHTSA
proposed that the propulsion batteries be recharged after each
increment of 40 burnish stops until each burnish procedure is complete
(S6.2.2 of Standard No. 105 and
[[Page 46911]]
S6.3.11.2 of Standard No. 135). Charging at a more frequent interval
would be permitted if the vehicle were incapable of achieving the
initial burnish test speed during a 40-stop sequence. In addition, the
manufacturer would be permitted the option of recharging by external
means or by substituting other propulsion batteries at 95 per cent or
greater charge. This proposal was supported by the commenters, and is
adopted in the final rule. Notice 10 also proposed that, if an EV has a
manual control for setting the level of regenerative braking, at the
beginning of each burnish procedure the control would be set to provide
maximum regenerative braking throughout each burnish. There were no
comments on this proposal, and it is adopted.
In GM's view, the brake burnishing procedures proposed for S6.2.2
of Standard No. 105 are not clear with respect to the propulsion
battery state of charge at the beginning of the tests. GM recommended
that the final rule be consistent with the burnish procedures adopted
for Standard No. 135. GM is correct, and paragraph S6.2.2 as adopted
specifies that the state of charge of the propulsion battery(s) at the
beginning of each burnish procedure is not less than 95 percent of full
charge. This modification is also consistent with the burnishing
requirements and procedures adopted in Standard No. 135.
C. Procedure for Charging Batteries
Notice 10 proposed that each burnish procedure and each braking
test procedure be initiated with the EV's propulsion batteries at a
state of charge of not less than 95 percent. Paragraphs S6.2.2 and
S6.2.3 of Standard No. 105 and paragraph S6.3.11 of Standard No. 135
read in part as follows: ``At the beginning of each performance test in
the test sequence (S7.3, S7.5, S7.7 through S7.11, and S7.14 through
S7.19 of this standard), unless otherwise specified, an EV's propulsion
battery(s) are at a state or charge of not less than 95 percent (the
batteries may be charged by external means or replaced by batteries
that are at a state of charge of not less than 95 percent)''.
GM commented that the phrase ``or fully charged per the
manufacturer's recommended procedure'' should be added to the
specifications for charging EV batteries. In its view, adding the
phrase will avoid potential conflicts and ambiguities for cases in
which the EV charging system is not designed to charge the battery(s)
to 95 percent of capacity. According to GM, extreme high and low states
of charge should be avoided to maximize battery life expectancy. GM
believes the manufacturer's recommended procedure for charging
batteries may be especially important for hybrid vehicles with on-board
chargers since these battery(s) may be designed to operate in a narrow
state of charge range.
Chrysler stated that all its EVs are equipped with an on-board
battery management system that controls battery charging, discharging,
and overall performance. The EV brake testing requirements in the final
rule should specify that the manufacturer's recommended energy charging
and measuring procedures be utilized, if available.
NHTSA agrees that the manufacturer's procedures should be used for
charging the propulsion batteries for performance tests as well as
burnishing if such procedures are available.
The agency is changing the amendments proposed in Notice 10
requiring that battery(s) be at a state of charge of not less than 95
percent at the beginning of each test procedure. The state of charge
requirement is being expanded to allow the battery(s) to be charged in
accordance with procedures recommended by the vehicle manufacturer. If
a battery charging procedure or a state of charge measurement procedure
is permanently attached to the vehicle or published in the vehicle
operator's manual, the procedure will be utilized during brake testing.
If the manufacturer does not provide a procedure for charging the
propulsion battery(s), the procedure proposed in Notice 10 will be
utilized. Therefore, NHTSA is adopting paragraphs S6.2.2 and S6.2.3 of
Standard No. 105 and paragraph S6.3.11 of Standard No. 135 to read in
pertinent part as follows: ``* * * an EV's propulsion battery(s) are at
the maximum state of charge recommended by the manufacturer, as stated
in the vehicle operator's manual or on a label that is permanently
attached to the vehicle, or, if the manufacturer has made no
recommendation, at a state of charge of not less than 95 percent. If
battery(s) are replaced rather than re-charged, the replacement
battery(s) are charged and measured for state of charge in accordance
with these procedures.''
Chrysler is concerned that proposed paragraph S6.2.3 of Standard
No. 105 does not allow for charging during the test sequences listed
and that EVs may not be able to complete the tests without recharging.
Notice 10 did not propose procedures for re-charging during the
test sequences because NHTSA did not believe that such re-charging
would be necessary. However, the agency now realizes that the
propulsion battery(s) may be depleted such that the vehicle
automatically shuts-down, reaches a point at which it will not
accelerate, or the low state of charge lamp is illuminated (Standard
No. 105, proposed paragraph S5.3.1). If any of these conditions occur,
during a test sequence, the final rule permits the vehicle to be
accelerated to brake test speed by auxiliary means since some tests are
required to be conducted within a time limit that would preclude re-
charging or replacing the battery(s) with one that is fully charged.
Accordingly, paragraph S6.2.3 of Standard No. 105 and paragraph
S6.3.11.3 of Standard No. 135, as adopted, clarify this. Each states
that ``* * * No further charging of the propulsion batteries occurs
during any of the performance tests in the test sequence of this
standard. If the propulsion batteries are depleted during a test
sequence such that the vehicle reaches automatic shut-down, will not
accelerate, or the low state of charge brake warning lamp is
illuminated, the vehicle is to be accelerated to brake test speed by
auxiliary means until the test sequence is completed.''
By adopting this test condition, NHTSA intends that the batteries
be essentially at full charge at the beginning of each test sequence.
D. Testing in Gear as Opposed to Testing in Neutral
This issue involves testing EVs in which RBS is not part of the
service brake system. For such vehicles, Notice 10 proposed to amend
Standards Nos. 105 (S6.2.4(b)) and No. 135,(S6.3.13) to state that
``the RBS is operational and set to produce the maximum regenerative
braking effect during the burnish tests, and is disabled during the
test procedures.''
GM commented that the requirement that a RBS that is not part of
the service brake system be disabled for all tests other than
burnishing tests is in conflict with other test procedures. Some of the
test procedures in both Standards Nos. 105 and 135 require that the
vehicle be tested with the transmission in gear. If an EV has a RBS
that is not part of the service brake system and the RBS is designed to
operate when the transmission is in gear, the RBS would have to be
disconnected for the in-gear test procedures. GM recommends that the
standards state that the RBS need not be disabled for in-gear braking
if the RBS can be disabled only through ``tampering'' when the
transmission is in gear. GM notes that the number of tests affected is
relatively small and the
[[Page 46912]]
high state of charge required at the beginning of these tests will
result in a low level of regenerative braking.
Chrysler remarked that when internal combustion engine (ICE)
vehicles are tested in gear, they take advantage of the braking effects
of the engine and transmission. Chrysler believes that EVs should be
allowed to use their RBS for in-gear testing since it is analogous to
the engine and transmission braking effects in ICE vehicles.
In Nissan's opinion, RBS should be allowed to be operational during
the in-gear brake testing procedures, whether or not the RBS is part of
the service brake system.
Toyota believes that the heating snub test, proposed paragraph
S7.13 of Standard No. 135, should be conducted in the ``in-gear'' mode,
to be consistent with the burnishing tests and to conform with ICE
vehicle testing.
Finally, Honda commented that, since the proposed test conditions
in both standards require that the drive line be engaged during the
braking procedures, the ``in gear'' testing specification should be
changed to allow the option of testing in neutral for vehicles with RBS
that is activated when the transmission is in gear.
NHTSA agrees with GM that a requirement to conduct certain tests in
gear with the RBS disconnected would conflict with the design of many
EVs. For these designs, the RBS is activated when the vehicle is in
gear and deactivated in the neutral transmission position. For EVs in
which the RBS is not part of the service brake system, meeting the
proposed test conditions would, as previously written, require
``tampering'' with the RBS to disengage it while the vehicle is in
gear. If the RBS is disengaged when the transmission is in the neutral
position, these tests can be conducted in neutral, as suggested by
Honda. The agency disagrees with the GM statement that most of the test
procedures are conducted in neutral. While this is true for Standard
No. 135, there are a significant number of in-gear test procedures in
Standard No. 105.
NHTSA agrees with Chrysler that the RBS functions in much the same
manner in EVs as does the engine and transmission braking effect in ICE
vehicles. If the RBS is active, it provides vehicle deceleration forces
in a manner similar to the engine and transmission for an ICE vehicle.
However, if the RBS is not part of the service brake system, its use is
optional in most cases. There is no assurance when the RBS is not part
of the service brake system that it will be engaged or activated by the
driver at any given time. This is the primary reason Notice 10 proposed
that the test procedures be conducted with the RBS non-functional if
the RBS is not part of the service brake system.
NHTSA also disagrees with Toyota's recommendation that the heating
snub test in proposed paragraph S7.13 of Standard No. 135 be conducted
with the RBS engaged. The same reasoning applies in the case of heating
snubs, that is, if the RBS is not part of the service brake system, its
use will be optional in most cases, and there is no assurance when the
RBS is not part of the service brake system that it will be engaged or
activated by the driver at any given time.
NHTSA has decided that the requirements proposed in Notice 10 for
vehicles in which the RBS is not part of the service brake system need
to be modified to address in-gear testing. Thus, the final rule
requires that manufacturers render RBS inoperative, including placing
the transmission in the neutral position if the RBS is deactivated in
neutral, during testing under conditions that would otherwise require
the vehicle to be in gear.
Accordingly, paragraph S6.2.4(b) of Standard No. 105 and paragraph
S6.3.13 of Standard No. 135 are adopted to read as follows: ``For an EV
equipped with an RBS that is not part of the service brake system, the
RBS is operational and set to produce the maximum regenerative braking
effect during the burnish tests, and is disabled during the test
procedures. If the vehicle is equipped with a neutral position that
automatically disables the RBS, the test procedures which are
designated to be conducted in gear may be conducted in neutral.''
E. Testing at Low State of Charge
(i) Low state of charge measurement. With respect to state of
charge of the propulsion batteries, paragraph S6.2.6 proposed in Notice
10 in part that: ``A vehicle equipped with electrically-actuated
service brakes also performs the tests specified in S7.3, S7.5, S7.7
through S7.11, and S7.13 through S7.19 of this standard with the
batteries providing power to those electrically-actuated brakes, at the
beginning of each test, in a depleted state of charge for condition
(a), (b), or (c) of this paragraph as appropriate.'' Proposed paragraph
S6.3.12 of Standard No. 135 was similar. Paragraphs S6.2.6(a) and
S6.2.6(b) of Standard No. 105 would require that propulsion battery(s)
used to power electrically-actuated service brakes be at a state of
charge that is not more than two percent and not less than one percent
above the state of charge that would shut down the propulsion system or
activate the brake failure warning lamp. Paragraph S6.2.6(c) of
Standard No. 105 would require that auxiliary battery(s) that are used
to power electrically-actuated service brakes be at a state of charge
that is not more than two percent and not less than one percent above
the state of charge that would activate the brake failure warning lamp.
Toyota, GM, and Nissan commented on the conditions and procedures
proposed in Notice 10 for paragraphs S6.2.6 (a) and (b) of Standard No.
105 in which the propulsion battery(s) are used to power electrically-
actuated service brakes. These commenters recommended that the test
conditions be modified to reduce the burden of the state of charge
measurement technique. The commenters argued that, with current
technology, it would be extremely difficult for many test facilities to
measure the state of charge with one or two percent accuracy. These
commenters recommended that the agency adopt a five percent initial
battery(s) state of charge for testing under S6.2.6 of Standard No. 105
and S6.3.12 of Standard No. 135.
Based on these comments, NHTSA believes that the one to two percent
state of charge range proposed as the initial test condition for the
propulsion and auxiliary battery(s) used in low state of charge tests
would be difficult to measure. A five percent state of charge would not
appreciably change the stringency of the requirements, but would
substantially reduce the state of charge measurement burden.
For these reasons, Standard No. 135 (S6.3.12(c)), as adopted, will
state that ``* * * the auxiliary battery(s) is at not more than five
percent above the actual state of charge at which the brake failure
warning signal, required by S5.5.1(e) of this standard, is
illuminated.'' The propulsion battery(s) referenced in S6.3.12 (a) and
(b) of Standard No. 135 will also be charged to not more than five
percent above the state of charge that would cause shut down or
illumination of the brake failure warning lamp. The auxiliary
battery(s) in paragraph S6.2.6(c) of Standard No. 105, and the
propulsion battery(s) in paragraphs S6.2.6 (a), and (b), will be
charged to not more than five percent above the state of charge that
would illuminate the brake system indicator lamp as required in
S5.3.1(e), or the state of charge that would result in automatic shut-
down of the propulsion system.
(ii) Low State of charge testing. The agency proposed in Notice 10
that EVs with electrically actuated service brakes be required to
complete a series of brake performance tests with the battery(s) at
[[Page 46913]]
a low state of charge. With respect to the state of charge of
propulsion batteries, paragraph S6.2.6 of Standard No. 105 proposed in
part that: ``A vehicle equipped with electrically-actuated service
brakes also performs the tests specified in S7.3, S7.5, S7.7, through
S7.11, and S7.13 through S7.19 of this standard with the battery(s)
providing power to those electrically-actuated brakes, at the beginning
of each test, in a depleted state of charge for condition (a), (b), or
(c) of this paragraph as appropriate.'' To the same effect was proposed
paragraph S6.3.12 of Standard No. 135.
The agency argued that a vehicle that can be operated should be
able to perform a full series of brake tests. The agency further stated
that the purpose of the test series is to assure that a vehicle will
operate properly if any one of the test conditions occur during
operation.
GM, in its comments to Notice 10, continued to express the concern
it expressed in response to Notice 7. That is, the requirement for a
full series of tests under depleted battery(s) conditions is
unreasonable and unnecessary. All commenters responding to Notice 7
indicated that it was unreasonable and unnecessary to subject an EV to
a complete brake test series with depleted battery(s). They indicated
that a vehicle with a low state of charge in the propulsion battery(s)
could be expected to perform a low number of accelerations prior to
becoming immobile. The commenters argued that it was unreasonable to
require braking capacity that far exceeds propulsion capacity.
After further consideration, the agency agrees that a full series
of tests is not necessary because it is very unlikely that a vehicle
with a low state of charge would require the braking capacity needed to
perform an entire brake test series under either Standard No. 105 or
Standard No. 135. NHTSA also believes that current propulsion
battery(s) would need substantial redesign to comply with the proposed
requirements.
GM requested that the agency reconsider the procedure for a
dedicated low charge braking test that the company had recommended in
its comments to Notice 7.
The agency feels that an abbreviated braking test procedure similar
to the one recommended by GM in its comments to Notice 7 is
appropriate, and that it is sufficient for an EV with electrically-
actuated service brakes to demonstrate braking power while it can still
be accelerated.
GM also indicated that the recharging procedures for these tests
needed clarification. The proposed test procedure for low battery(s)
state of charge testing specified in Notice 10 does not allow for
recharging, but states that a vehicle may be accelerated to test speed
by auxiliary means. The test procedures adopted in the final rule do
not allow for recharging of the battery(s) that provide power for
electrically-actuated service brakes. An auxiliary means is to be
provided as necessary to accelerate the vehicle to test speed, as
proposed in Notice 10.
The agency is specifying that an abbreviated low state of charge
braking performance test series be conducted on EVs utilizing
electrically-actuated service brakes. In addition, S6.2.6 of Standard
No. 105 and S6.3.12 of Standard No. 135 are adopted to read: ``A
vehicle equipped with electrically-actuated service brakes also
performs the following test series. Conduct 10 stopping tests from a
speed of 100 kph or the maximum vehicle speed, whichever is less. At
least two of the 10 stopping distances must be less than or equal to 70
meters. The vehicle is to be loaded to GVWR for these tests and the
transmission shall be in the neutral position when the service brake
control is actuated and throughout the remainder of the test. The
battery(s) providing power to those electrically-actuated service
brakes, at the beginning of each test, shall be in a depleted state of
charge for conditions (a), (b), or (c) of this paragraph as
appropriate. An auxiliary means may be used to accelerate an EV to test
speed.''
Nissan believed that it is not technically feasible to detect state
of charge of an auxiliary battery and recommends that the agency delete
the low state of charge performance tests for vehicles with auxiliary
batteries that provide power for vacuum boosters and hydraulic pumps
(electrically-actuated brakes).
Nissan believes that actual fluid pressure or vacuum should be
monitored instead of the state of charge of an auxiliary battery in
vehicles which have electrically-actuated service brakes. Notice 10 did
not propose that auxiliary battery(s) that are used to power hydraulic
pumps or vacuum motors be monitored for state of charge. The proposed
requirement applies to auxiliary battery(s) that power electrically-
actuated service brakes, brakes in which the brake control signal is
electrically transmitted from the brake control unit to the foundation
brakes, and RBS that is part of the service brake system. Auxiliary
battery(s) that power hydraulic pumps and vacuum motors are not
included under the proposed requirement for state of charge monitoring.
No action is taken in response to this comment.
7. Issues Related to Test Conditions
A. Initial Brake Temperature (IBT)
HQ believes that its braking system will not achieve the IBT
required in section S7 Road test procedures and performance
requirements of Standard No. 135 for the foundation or friction brakes
when the heating tests are conducted because a large percentage of the
braking forces are supplied by dynamic (dissipative) braking. HQ
suggests that the IBT condition be made optional for EVs as well as the
test sequence S7.13-S7.16 because the HQ dynamic braking system will
develop low temperatures in the friction brake system components.
NHTSA agrees that the dynamic braking forces (RBS-type) of the HQ
braking system could result in low brake temperatures for the
foundation friction brakes. Neither Standard No. 105 nor Standard No.
135 specify procedures for establishing the IBT for those test
procedures that require an initial brake temperature. The agency
believes that the IBT condition can be met if several stops are
performed with the RBS disabled or disengaged, and that disabling or
disengaging the RBS system would not be impracticable. The agency also
believes that the hot performance and recovery performance tests in
paragraphs S7.13 through S7.16 of Standard No. 135 are an extremely
important phase of the overall brake testing and that all vehicles with
friction brakes should perform these tests. Thus, it has made no
modifications in adopting the IBT condition as proposed.
B. Static Parking Brake Test
Proposed S7.7.1.3 in Standard No. 105 and S7.12.2(o) in Standard
No. 135 would add language to clarify the means for activating electric
parking brakes, to state ``[f]or vehicles with electrically activated
parking brakes, apply the parking brakes by activating the parking
brake control.'' NHTSA has adopted the proposed change.
C. Stops With Engine Off (Standard No. 135)
HQ believes that the vehicle engine off condition for brake testing
(S7.7.2(a)) represents engine stalling for internal combustion engine
vehicles and has no direct equivalent for EVs. However, the
specification that the test is conducted with ``no electromotive
force'' applied to the motor(s) proposed in paragraph S7.7.3(h) of
Standard No. 135 is intended to serve the same purpose for
[[Page 46914]]
EVs as testing ICE vehicles with the engine off.
Nevertheless, HQ believes that the term needs further explanation
since it is not clear whether regenerative braking using the electric
motor(s) is allowed under S7.7.3(h). The proposed conditions of
S7.7.3(h) for EVs during tests that are analogous to ICE vehicle tests
with the engine off specify that the electric propulsion motor(s) not
be supplied with any electromotive force, or be switched-off. The RBS
is not allowed to operate under these test conditions. No amendment of
the proposal is required, and S7.7.3(h) is adopted as proposed.
8. International Harmonization
The European Community has not finalized braking standards for EVs
to date, and the conditions and procedures for EV testing specified in
this final rule may be adopted by the Europeans.
NHTSA has been recently provided a current copy of draft Regulation
13-H (R13-H), the European version of the harmonized brake standard for
light passenger vehicles. The draft was reviewed with respect to EV
braking conditions and requirements to determine if they are compatible
with the EV brake test conditions and requirements in this final rule.
In general, EV brake system design and performance requirements in
Standard No. 135 and R13-H are similar. For example, both rules account
for RBS and both rules distinguish RBS that is part of the service
brake system from RBS that is not. At this time, NHTSA does not
anticipate that harmonization of the brake standards will be more
difficult for EVs than for conventional vehicles.
In general, R13-H has specified more EV test procedures and
conditions than the agency has specified in Standard No. 135 as amended
by this final rule since the Europeans have more EV experience at this
time. The R-13H draft does not, however, address EV recharging during
testing or electrically-actuated service brakes for passenger cars. As
NHTSA's experience increases, it may propose adding specific EV test
procedures and conditions to the adhesion utilization requirements and
other areas of performance.
Whatever future actions NHTSA takes in this area, it will discuss
requirements for EV brake systems with braking experts from other
nations. It should be possible for all regulatory authorities to reach
a consistent harmonized approach when dealing with an emerging
technology like EV brake systems.
The reader will find that provisions of this final rule not
discussed by this notice are substantially the same as those proposed
by Notice 10.
Effective Dates (Lead Time)
Notice 10 proposed that EV amendments to Standards Nos. 105 and 135
become effective 30 days after publication of the final rule.
Chrysler and Ford stated that one year after publication of the
final rule would be preferable; if the standard is further amended,
more lead time may be required for compliance to make necessary design
modifications. However, an early effective date was supported by GM
which wishes to certify its EV-1 passenger car to electric vehicle
braking requirements at the earliest possible date.
NHTSA believes that the final rule is written in such a manner as
to accommodate most present EV brake system designs without extensive
modifications. But it is sensitive to the comments by Ford and Chrysler
that each may need up to one year for leadtime, should they deem it
necessary to modify their current EV braking system designs to meet the
standards promulgated by this document.
To accommodate all commenters on this issue, NHTSA is adopting an
early effective date for the electric brake amendments with mandatory
compliance after one year. The amendments to Standard No. 105, which do
not change the present requirements relating to hydraulic brake
systems, will become effective 45 days after their publication.
However, manufacturers of passenger cars, multipurpose passenger
vehicles, trucks, and buses, with electric brake systems, need not
comply until September 1, 1998. Manufacturers of passenger cars with
hydraulic brake systems already have the option of meeting Standard No.
105 until September 1, 2000, and this same option is being afforded
passenger cars with electric brake systems, under companion amendments
to both Standards Nos. 105 and 135. To accomplish this, Section S3
Application of Standard No. 105 is being amended to read as follows:
``S3 Application
(a) This standard applies to the following vehicles with hydraulic
or electric brake systems: multipurpose passenger vehicles, trucks, and
buses, and to passenger cars manufactured before September 1, 2000.
(b) This standard, at the option of a manufacturer of a passenger
car, multipurpose passenger vehicle, truck, or bus, with an electric
brake system, does not apply before September 1, 1998.
(c) At the option of the manufacturer, passenger cars with
hydraulic or electric brake systems manufactured before September 1,
2000, may comply with the requirements of Federal Motor Vehicle Safety
Standard No. 135, Passenger Car Brake Systems, instead of the
requirements of this standard.''
Compliance with Standard No. 135 is not mandatory until September
1, 2000, although manufacturers of passenger cars with hydraulic brake
systems have the present option of complying with it as an alternative
to Standard No. 105. The amendments made by this document do not affect
the hydraulic brake requirements, but add requirements applicable to
electric vehicle brakes and are incorporated into it effective 45 days
after publication. The application section of Standard No. 135 is being
amended to read:
``S3 Application. This standard applies to passenger cars
manufactured on or after September 1, 2000. In addition, passenger
cars manufactured before September 1, 2000 may, at the option of the
manufacturer, meet the requirements of this standard instead of
Federal Motor Vehicle Safety Standard No. 105 Hydraulic and Electric
Brake Systems.''
In summary, passenger cars, multipurpose passenger vehicles,
trucks, and buses, with electric brake systems need not comply with
Standard No. 105 until September 1, 1998, and may comply before then.
But all these vehicles must comply with Standard No. 105 on and after
September 1, 1998. Alternatively, passenger cars with electric brake
systems may comply with Standard No. 135 at any time before September
1, 2000, but otherwise must meet Standard No. 105 as of September 1,
1998, and Standard No. 135 as of September 1, 2000.
Because of the wish of some manufacturers to offer and certify
complying vehicles with electric brake systems at an early date, and
because the amendments do not affect existing requirements for vehicles
with hydraulic brake systems, it is hereby found that an effective date
earlier than 180 days after issuance of the amendments is in the public
interest. Accordingly, the amendments are effective October 20, 1997.
Regulatory Analysis
Executive Order 12866 (Regulatory Planning and Review) and DOT
Regulatory Policies and Procedures
This rulemaking has not been reviewed under Executive Order 12866.
NHTSA has considered the economic implications of this regulation and
determined that it is not significant within the meaning of the DOT
[[Page 46915]]
Regulatory Policies and Procedure. It does not initiate a substantial
regulatory program or involve a change in policy.
Regulatory Flexibility Act
The agency has also considered the effects of this rulemaking
action in relation to the Regulatory Flexibility Act. I certify that
this rulemaking action will not have a significant economic effect upon
a substantial number of small entities. Motor vehicle manufacturers are
generally not small businesses within the meaning of the Regulatory
Flexibility Act. Accordingly, no Regulatory Flexibility Analysis has
been prepared.
Executive Order 12612 (Federalism)
This action has been analyzed in accordance with the principles and
criteria contained in Executive Order 12612 on ``Federalism.'' It has
been determined that the rulemaking action does not have sufficient
federalism implications to warrant the preparation of a Federalism
Assessment.
National Environmental Policy Act
NHTSA has analyzed this rulemaking action for purposes of the
National Environmental Policy Act. The rulemaking action will not have
a significant effect upon the environment. There is no environmental
impact associated with adaptation of test procedures to make them more
appropriate for vehicles already required to comply with the Federal
motor vehicle safety standards. The rulemaking action would not have a
direct effect. However, to the extent that this rulemaking might
facilitate the introduction of EVs which are powered by an electric
motor drawing current from rechargeable storage batteries, fuel cells,
or other portable sources of electric current, and which may include a
nonelectrical source of power designed to charge batteries and
components thereof, the rulemaking would have a beneficial effect upon
the environment and reduce fuel consumption because EVs emit no
hydrocarbon emissions and do not depend directly upon fossil fuels to
propel them.
Executive Order 12778 (Civil Justice Reform)
This rule will not have any retroactive effect. Under 49 U.S.C.
30103, whenever a Federal motor vehicle safety standard is in effect, a
state may not adopt or maintain a safety standard applicable to the
same aspect of performance which is not identical to the Federal
standard. Section 30161 of Title 49 sets forth a procedure for judicial
review of final rules establishing, amending or revoking Federal motor
vehicle safety standards. That section does not require submission of a
petition for reconsideration or other administrative proceedings before
parties may file suit in court.
List of Subjects in 49 CFR Part 571
Imports, Motor vehicle safety, Motor vehicles
PART 571--FEDERAL MOTOR VEHICLE SAFETY STANDARDS
In consideration of the foregoing, 49 CFR part 571 is amended as
follows:
1. The authority citation for Part 571 continues to read as
follows:
Authority: 49 U.S.C. 322, 30111, 30115, 30117, 30166; delegation
of authority at 49 CFR 1.50.
Sec. 571.105 [Amended]
2. Section 571.105 is amended by:
a. Revising its heading;
b. Revising S1, S3, the definitions of ``backup system'' and
``split service brake system'' in S4 and adding to S4, in alphabetical
order, definitions of ``Electric vehicle or EV'', ``Electrically-
actuated service brakes'', and ``Regenerative braking system or RBS'';
c. Amending S5.1.1.4 to add a sentence at the end thereof below the
undesignated table;
d. Adding S5.1.2.3, S5.1.2.4, and S5.1.3.5;
e . Revising the introductory text of S5.3.1 and adding S5.3.1 (e),
(f), and (g);
f. Revising the introductory text of S5.3.5(c)(1) and S5.4.3;
g. Withdrawing the revision of S5.5 and additions of S5.5.1 and
S5.5.2 published at 60 FR 13256, Mar. 10, 1995, and the revision of
S5.5.1 published at 60 FR 63979, Dec. 13, 1995 that were to become
effective March 1, 1999, and revising S5.5 as currently in effect and
adding S5.5.1 and S5.5.2;
h. Adding S6.2 through S6.2.6;
i. Revising the introductory text of S7.7.1.3 and adding
S7.7.1.3(c);
j. Adding S7.9.5 and S7.9.6; and
k. Adding S7.10.3
The revised and added heading and paragraphs read as follows:
Sec. 571.105 Standard No. 105; Hydraulic and electric brake systems.
S1. Scope. This standard specifies requirements for hydraulic and
electric service brake systems, and associated parking brake systems.
* * * * *
S3. Application.
(a) This standard applies to the following vehicles with hydraulic
or electric brake systems: multipurpose passenger vehicles, trucks, and
buses, and to passenger cars manufactured before September 1, 2000.
(b) This standard, at the option of a manufacturer of a passenger
car, multipurpose passenger vehicle, truck, or bus, with an electric
brake system, does not apply before September 1, 1998.
(c) At the option of the manufacturer, passenger cars with
hydraulic or electric brake systems manufactured before September 1,
2000, may comply with the requirements of Federal Motor Vehicle Safety
Standard No. 135, Passenger Car Brake Systems, instead of the
requirements of this standard.
S4. Definitions.
* * * * *
Backup system means a portion of a service brake system, such as a
pump, that automatically supplies energy, in the event of a primary
brake power source failure.
* * * * *
Electric vehicle or EV means a motor vehicle that is powered by an
electric motor drawing current from rechargeable storage batteries,
fuel cells, or other portable sources of electrical current, and which
may include a non-electrical source of power designed to charge
batteries and components thereof.
Electrically-actuated service brakes means service brakes that
utilize electrical energy to actuate the foundation brakes.
* * * * *
Regenerative braking system or RBS means an electrical energy
system that is installed in an EV for recovering or dissipating kinetic
energy, and which uses the propulsion motor(s) as a retarder for
partial braking of the EV while returning electrical energy to the
propulsion batteries or dissipating electrical energy.
* * * * *
Split service brake system means a brake system consisting of two
or more subsystems actuated by a single control, designed so that a
single failure in any subsystem (such as a leakage-type failure of a
pressure component of a hydraulic subsystem except structural failure
of a housing that is common to two or more subsystems, or an electrical
failure in an electric subsystem) does not impair the operation of any
other subsystem.
* * * * *
S5.1.1.4 * * * For an EV, the speed attainable in 2 miles is
determined with the propulsion batteries at a state of charge of not
less than 95 percent at the beginning of the run.
S5.1.2 Partial failure.
* * * * *
[[Page 46916]]
S5.1.2.3 For a vehicle manufactured with a service brake system in
which the brake signal is transmitted electrically between the brake
pedal and some or all of the foundation brakes, regardless of the means
of actuation of the foundation brakes, the vehicle shall be capable of
stopping from 60 mph within the corresponding distance specified in
Column IV of Table II with any single failure in any circuit that
electrically transmits the brake signal, and with all other systems
intact.
S5.1.2.4 For an EV manufactured with a service brake system that
incorporates RBS, the vehicle shall be capable of stopping from 60 mph
within the corresponding distance specified in Column IV of Table II
with any single failure in the RBS, and with all other systems intact.
* * * * *
S5.1.3.5 Electric brakes. Each vehicle with electrically-actuated
service brakes (brake power unit) shall comply with the requirements of
S5.1.3.1 with any single electrical failure in the electrically-
actuated service brakes and all other systems intact.
* * * * *
S5.3 Brake system indicator lamp. * * *
S5.3.1 An indicator lamp shall be activated when the ignition
(start) switch is in the ``on'' (``run'') position and whenever any of
the conditions (a) or (b), (c), (d), (e), (f), and (g) occur:
* * * * *
(e) For a vehicle with electrically-actuated service brakes,
failure of the source of electric power to the brakes, or diminution of
state of charge of the batteries to less than a level specified by the
manufacturer for the purpose of warning a driver of degraded brake
performance.
(f) For a vehicle with electric transmission of the service brake
control signal, failure of a brake control circuit.
(g) For an EV with RBS that is part of the service brake system,
failure of the RBS. An amber lamp may be used displaying the symbol
``RBS.'' RBS failure in a system that is part of the service brake
system may also be indicated by an amber lamp that also indicates ABS
failure and displays the symbol ``ABS/RBS''.
* * * * *
S5.3.5 * * *
(c)(1) If separate indicators are used for one or more of the
conditions described in S5.3.1(a) through S5.3.1(g) of this standard,
the indicator display shall include the word ``Brake'' and appropriate
additional labeling, except as provided in (c)(1) (A) through (D) of
this paragraph.
* * * * *
S5.4.3 Reservoir labeling--Each vehicle equipped with hydraulic
brakes shall have a brake fluid warning statement that reads as
follows, in letters at least one-eighth of an inch high: ``WARNING,
Clean filler cap before removing. Use only ______ fluid from a sealed
container.'' (Inserting the recommended type of brake fluid as
specified in 49 CFR 571.116, e.g., ``DOT 3''). The lettering shall be--
* * *
S5.5 Antilock and variable proportioning brake systems.
S5.5.1 On and after March 1, 1999, each vehicle with a GVWR greater
than 10,000 pounds, except for any vehicle that has a speed attainable
in 2 miles of not more than 33 mph, shall be equipped with an antilock
brake system that directly controls the wheels of at least one front
axle and the wheels of at least one rear axle of the vehicle. On and
after March 1, 1999, on each vehicle with a GVWR greater than 10,000
pounds but not greater than 12,000 pounds, the antilock brake system
may also directly control the wheels of the drive axle by means of a
single sensor in the drive line. Wheels on other axles of the vehicle
may be indirectly controlled by the antilock brake system.
S5.5.2 In the event of any failure (structural or functional) in an
antilock or variable proportioning brake system, the vehicle shall be
capable of meeting the stopping distance requirements specified in
S5.1.2 for service brake system partial failure. For an EV that is
equipped with both ABS and RBS that is part of the service brake
system, the ABS must control the RBS.
* * * * *
S6.2 Electric vehicles and electric brakes.
S6.2.1 The state of charge of the propulsion batteries is
determined in accordance with SAE Recommended Practice J227a, Electric
Vehicle Test Procedure, February 1976. The applicable sections of J227a
are 3.2.1 through 3.2.4, 3.3.1 through 3.3.2.2, 3.4.1 and 3.4.2, 4.2.1,
5.2, 5.2.1, and 5.3.
S6.2.2 At the beginning of the first effectiveness test specified
in S7.3, and at the beginning of each burnishing procedure, each EV's
propulsion battery is at the maximum state of charge recommended by the
manufacturer, as stated in the vehicle operator's manual or on a label
that is permanently attached to the vehicle, or, if the manufacturer
has made no recommendation, at a state of charge of not less than 95
percent. If a battery is replaced rather than recharged, the
replacement battery is to be charged and measured for state of charge
in accordance with these procedures. During each burnish procedure,
each propulsion battery is restored to the recommended state of charge
or a state of charge of not less than 95 percent after each increment
of 40 burnish stops until each burnish procedure is complete. The
batteries may be charged at a more frequent interval if, during a
particular 40-stop increment, the EV is incapable of achieving the
initial burnish test speed. During each burnish procedure, the
propulsion batteries may be charged by an external means or replaced by
batteries that are charged to the state of charge recommended by the
manufacturer or a state of charge of not less than 95 percent. For EVs
having a manual control for setting the level of regenerative braking,
the manual control, at the beginning of each burnish procedure, is set
to provide maximum regenerative braking throughout the burnish.
S6.2.3 At the beginning of each performance test in the test
sequence (S7,3, S7.5, S7.7 through S7.11, and S7.13 through S7.19 of
this standard), unless otherwise specified, each propulsion battery of
an EV is at the maximum state of charge recommended by the
manufacturer, as stated in the vehicle operator's manual or on a label
that is permanently attached to the vehicle, or, if the manufacturer
has made no recommendation, at a state of charge of not less than 95
percent. If batteries are replaced rather than recharged, each
replacement battery shall be charged and measured for state of charge
in accordance with these procedures. No further charging of any
propulsion battery occurs during any of the performance tests in the
test sequence of this standard. If the propulsion batteries are
depleted during a test sequence such that the vehicle reaches automatic
shut-down, will not accelerate, or the low state of charge warning lamp
is illuminated, the vehicle is to be accelerated to brake test speed by
auxiliary means.
S6.2.4 (a) For an EV equipped with RBS, the RBS is considered to be
part of the service brake system if it is automatically controlled by
an application of the service brake control, if there is no means
provided for the driver to disconnect or otherwise deactivate it, and
if it is activated in all transmission positions, including neutral.
The RBS is operational during all burnishes and all tests, except for
the test of a failed RBS.
(b) For an EV equipped with an RBS that is not part of the service
brake system, the RBS is operational and set
[[Page 46917]]
to produce the maximum regenerative braking effect during the
burnishes, and is disabled during the test procedures. If the vehicle
is equipped with a neutral gear that automatically disables the RBS,
the test procedures which are designated to be conducted in gear may be
conducted in neutral.
S6.2.5 For tests conducted ``in neutral,'' the operator of an EV
with no ``neutral'' position (or other means such as a clutch for
disconnecting the drive train from the propulsion motor(s)) does not
apply any electromotive force to the propulsion motor(s). Any
electromotive force that is applied to the propulsion motor(s)
automatically remains in effect unless otherwise specified by the test
procedure.
S6.2.6 A vehicle equipped with electrically-actuated service
brakes also performs the following test series. Conduct 10 stopping
tests from a speed of 100 kph or the maximum vehicle speed, whichever
is less. At least two of the 10 stopping distances must be less than or
equal to 70 meters. The vehicle is loaded to GVWR for these tests and
the transmission is in the neutral position when the service brake
control is actuated and throughout the remainder of the test. The
battery or batteries providing power to those electrically-actuated
brakes, at the beginning of each test, shall be in a depleted state of
charge for conditions (a), (b), or (c) of this paragraph as
appropriate. An auxiliary means may be used to accelerate an EV to test
speed.
(a) For an EV equipped with electrically-actuated service brakes
deriving power from the propulsion batteries, and with automatic shut-
down capability of the propulsion motor(s), the propulsion batteries
are at not more than five percent above the EV actual automatic shut-
down critical value. The critical value is determined by measuring the
state-of-charge of each propulsion battery at the instant that
automatic shut-down occurs and averaging the states-of-charge recorded.
(b) For an EV equipped with electrically-actuated service brakes
deriving power from the propulsion batteries, and with no automatic
shut-down capability of the propulsion motor(s), the propulsion
batteries are at an average of not more than five percent above the
actual state of charge at which the brake failure warning signal,
required by S5.3.1(e) of this standard, is illuminated.
(c) For a vehicle which has an auxiliary battery (or batteries)
that provides electrical energy to operate the electrically-actuated
service brakes, the auxiliary battery(batteries) is (are) at (at an
average of) not more than five percent above the actual state of charge
at which the brake failure warning signal, required by S5.3.1(e) of
this standard, is illuminated.
* * * * *
S7.7.1 Test procedure for requirements of S5.2.1.
* * * * *
S7.7.1.3 With the vehicle held stationary by means of the service
brake control, apply the parking brake by a single application of the
force specified in (a), (b), or (c) of this paragraph, except that a
series of applications to achieve the specified force may be made in
the case of a parking brake system design that does not allow the
application of the specified force in a single application:
* * * * *
(c) For a vehicle using an electrically-activated parking brake,
apply the parking brake by activating the parking brake control.
* * * * *
S7.9 Service brake system test--partial failure.
* * * * *
S7.9.5 For a vehicle in which the brake signal is transmitted
electrically between the brake pedal and some or all of the foundation
brakes, regardless of the means of actuation of the foundation brakes,
the tests in S7.9.1 through S7.9.3 of this standard are conducted by
inducing any single failure in any circuit that electrically transmits
the brake signal, and all other systems intact. Determine whether the
brake system indicator lamp is activated when the failure is induced.
S7.9.6 For an EV with RBS that is part of the service brake
system, the tests specified in S7.9.1 through S7.9.3 are conducted with
the RBS disconnected and all other systems intact. Determine whether
the brake system indicator lamp is activated when the RBS is
disconnected.
* * * * *
S7.10 Service brake system-inoperative brake power unit or brake
power assist unit test. (For vehicles equipped with brake power unit or
brake power assist unit.)
* * * * *
S7.10.3 Electric brakes.
(a) For vehicles with electrically-actuated service brakes, the
tests in S7.10.1 or S7.10.2 are conducted with any single electrical
failure in the electric brake system instead of the brake power or
brake power assist systems, and all other systems intact.
(b) For EVs with RBS that is part of the service brake system, the
tests in S7.10.1 or S7.10.2 are conducted with the RBS discontinued and
all other systems intact.
3. Section 571.135 is amended by:
a. Revising S3;
b. Revising the definitions of ``maximum speed'', and ``split
service brake system'' in S4, and adding in S4, in alphabetical order,
definitions for ``Electric vehicle'', ``Electrically-actuated service
brakes'', and ``Regenerative braking system'';
c. Adding S5.1.3;
d. Revising the introductory text of S5.4.3 and S5.5.1 and adding
S5.5.1 (e),(f), and (g);
e. Revising the introductory text of S5.5.5(d);
f. Adding S6.3.11.1, S6.3.11.2, S6.3.11.3, S6.3.12, and S6.3.13;
g. Adding S7.2.4(f), S7.4.5.1, and S7.7.3(h)
h. Revising S7.10, S7.10.3(f), and S7.10.4;
i. Adding S7.11.3 (m) and (n); and
j. Revising S7.12.2(i).
The revised and added paragraphs read as follows:
Sec. 571.135 Standard No. 135; Passenger Car Brake Systems.
* * * * *
S3 Application. This standard applies to passenger cars
manufactured on or after September 1, 2000. In addition, passenger cars
manufactured before September 1, 2000 may, at the option of the
manufacturer, meet the requirements of this standard instead of Federal
Motor Vehicle Safety Standard No. 105 Hydraulic and Electric Brake
Systems.
S4. Definitions.
* * * * *
Electric vehicle or EV means a motor vehicle that is powered by an
electric motor drawing current from rechargeable storage batteries,
fuel cells, or other portable sources of electrical current, and which
may include a non-electrical source of power designed to charge
batteries and components thereof.
Electrically-actuated service brakes means service brakes that
utilize electrical energy to actuate the foundation brakes.
* * * * *
Maximum speed of a vehicle or VMax means the highest speed
attainable by accelerating at a maximum rate from a standing start for
a distance of 3.2 km (2 miles) on a level surface, with the vehicle at
its lightly loaded vehicle weight, and, if an EV, with the propulsion
batteries at a state of charge of not less than 95 percent at the
beginning of the run.
* * * * *
[[Page 46918]]
Regenerative braking system or RBS means an electrical energy
system that is installed in an EV for recovering or dissipating kinetic
energy, and which uses the propulsion motor(s) as a retarder for
partial braking of the EV while returning electrical energy to the
propulsion battery(s) or dissipating electrical energy.
Split service brake system means a brake system consisting of two
or more subsystems actuated by a single control, designed so that a
single failure in any subsystem (such as a leakage-type failure of a
pressure component of a hydraulic subsystem except structural failure
of a housing that is common to two or more subsystems, or an electrical
failure in an electric subsystem) does not impair the operation of any
other subsystem.
* * * * *
S5.1.3 Regenerative braking system. (a) For an EV equipped with
RBS, the RBS is considered to be part of the service brake system if it
is automatically activated by an application of the service brake
control, if there is no means provided for the driver to disconnect or
otherwise deactivate it, and if it is activated in all transmission
positions, including neutral.
(b) For an EV that is equipped with both ABS and RBS that is part
of the service brake system, the ABS must control the RBS.
* * * * *
S5.4.3. Reservoir labeling. Each vehicle equipped with hydraulic
brakes shall have a brake fluid warning statement that reads as
follows, in letters at least 3.2 mm (\1/8\ inch) high: ``WARNING: Clean
filler cap before removing. Use only ______ fluid from a sealed
container.'' (Inserting the recommended type of brake fluid as
specified in 49 CFR 571.116, e.g.,``DOT 3.'') The lettering shall be:
* * * * *
S5.5.1. Activation. An indicator shall be activated when the
ignition (start) switch is in the ``on'' (``run'') position and
whenever any of conditions (a) through (g) occur:
* * * * *
(e) For a vehicle with electrically-actuated service brakes,
failure of the source of electric power to those brakes, or diminution
of state of charge of the batteries to less than a level specified by
the manufacturer for the purpose of warning a driver of degraded brake
performance.
(f) For a vehicle with electric transmission of the service brake
control signal, failure of a brake control circuit.
(g) For an EV with a regenerative braking system that is part of
the service brake system, failure of the RBS. An amber lamp may be used
displaying the symbol ``RBS.'' RBS failure in a system that is part of
the service brake system may also be indicated by an amber lamp that
also indicates ABS failure and displays the symbol ``ABS/RBS''.
* * * * *
S5.5.5. Labeling.
* * * * *
(d) If separate indicators are used for one or more of the
conditions described in S5.5.1(a) through S5.5.1(g), the indicators
shall display the following wording:
* * * * *
S6.3.11 State of charge of batteries for EVs.
S6.3.11.1 The state of charge of the propulsion batteries is
determined in accordance with SAE Recommended Practice J227a, Electric
Vehicle Test Procedure, February 1976. The applicable sections of J227a
are 3.2.1 through 3.2.4, 3.3.1 through 3.3.2.2, 3.4.1 and 3.4.2, 4.2.1,
5.2, 5.2.1 and 5.3.
S6.3.11.2 At the beginning of the burnish procedure (S7.1 of this
standard) in the test sequence, each propulsion battery is at the
maximum state of charge recommended by the manufacturer, as stated in
the vehicle operator's manual or on a label that is permanently
attached to the vehicle, of, if the manufacturer has made no
recommendation, not less than 95 percent. During the 200-stop burnish
procedure, the propulsion batteries are restored to the maximum state
of charge determined as above, after each increment of 40 burnish stops
until the burnish procedure is complete. The batteries may be charged
at a more frequent interval during a particular 40-stop increment only
if the EV is incapable of achieving the initial burnish test speed
during that increment. During the burnish procedure, the propulsion
batteries may be charged by external means or replaced by batteries
that are at a state of charge of not less than 95 percent. For an EV
having a manual control for setting the level of regenerative braking,
the manual control, at the beginning of the burnish procedure, is set
to provide maximum regenerative braking throughout the burnish.
S6.3.11.3 At the beginning of each performance test in the test
sequence (S7.2 through S7.17 of this standard), unless otherwise
specified, an EV's propulsion batteries are at the state of charge
recommended by the manufacturer, as stated in the vehicle operator's
manual or on a label that is permanently attached to the vehicle, or,
if the manufacturer has made no recommendation, at a state of charge of
not less than 95 percent. No further charging of any propulsion battery
occurs during any of the performance tests in the test sequence of this
standard. If the propulsion batteries are depleted during a test
sequence such that the vehicle reaches automatic shut-down, will not
accelerate, or the low state of charge brake warning lamp is
illuminated, the vehicle is to be accelerated to brake test speed by
auxiliary means. If a battery is replaced rather than recharged, the
replacement battery shall be charged and measured for state of charge
in accordance with these procedures.
S6.3.12 State of charge of batteries for electrically-actuated
service brakes. A vehicle equipped with electrically-actuated service
brakes also performs the following test series. Conduct 10 stopping
tests from a speed of 100 kph or the maximum vehicle speed, whichever
is less. At least two of the 10 stopping distances must be less than or
equal to 70 meters. The vehicle is loaded to GVWR and the transmission
is in the neutral position when the service brake control is actuated
and throughout the remainder of the test. Each battery providing power
to the electrically-actuated service brakes, shall be in a depleted
state of charge for conditions (a), (b), or (c) of this paragraph as
appropriate. An auxiliary means may be used to accelerate an EV to test
speed.
(a) For an EV equipped with electrically-actuated service brakes
deriving power from the propulsion batteries and with automatic shut-
down capability of the propulsion motor(s), the propulsion batteries
are at not more than five percent above the EV actual automatic shut-
down critical value. The critical value is determined by measuring the
state-of-charge of each propulsion battery at the instant that
automatic shut-down occurs.
(b) For an EV equipped with electrically-actuated service brakes
deriving power from the propulsion batteries and with no automatic
shut-down capability of the propulsion motor(s), the propulsion
batteries are at an average of not more than five percent above the
actual state of charge at which the brake failure warning signal,
required by S5.5.1(e) of this standard, is illuminated.
(c) For a vehicle which has one or more auxiliary batteries that
provides electrical energy to operate the electrically-actuated service
brakes, each auxiliary battery is at not more than five percent above
the actual state of charge at which the brake failure
[[Page 46919]]
warning signal, required by S5.5.1(e) of this standard, is illuminated.
S6.3.13 Electric vehicles.
S6.3.13.1 (a) For an EV equipped with an RBS that is part of the
service brake system, the RBS is operational during the burnish and all
tests, except for the test of a failed RBS.
(b) For an EV equipped with an RBS that is not part of the service
brake system, the RBS is operational and set to produce the maximum
regenerative braking effect during the burnish, and is disabled during
the test procedures. If the vehicle is equipped with a neutral gear
that automatically disables the RBS, the test procedures which are
designated to be conducted in gear may be conducted in neutral.
S6.3.13.2 For tests conducted ``in neutral'', the operator of an
EV with no ``neutral'' position (or other means such as a clutch for
disconnecting the drive train from the propulsion motor(s)) does not
apply any electromotive force to the propulsion motor(s). Any
electromotive force that is applied to the propulsion motor(s)
automatically remains in effect unless otherwise specified by the test
procedure.
* * * * *
S7.2.4 Performance requirements.
* * * * *
(f) An EV with RBS that is part of the service brake system shall
meet the performance requirements over the entire normal operating
range of the RBS.
* * * * *
S7.4.5 Performance requirements. * * *
S7.4.5.1 An EV with RBS that is part of the service brake system
shall meet the performance requirement over the entire normal operating
range of the RBS.
* * * * *
S7.7.3. Test conditions and procedures.
* * * * *
(h) For an EV, this test is conducted with no electromotive force
applied to the vehicle propulsion motor(s), but with brake power or
power assist still operating, unless cutting off the propulsion
motor(s) also disables those systems.
* * * * *
S7.10 Partial failure.
* * * * *
S7.10.3. Test conditions and procedures.
* * * * *
(f) Alter the service brake system to produce any single failure.
For a hydraulic circuit, this may be any single rupture or leakage type
failure, other than a structural failure of a housing that is common to
two or more subsystems. For a vehicle in which the brake signal is
transmitted electrically between the brake pedal and some or all of the
foundation brakes, regardless of the means of actuation of the
foundation brakes, this may be any single failure in any circuit that
electrically transmits the brake signal. For an EV with RBS that is
part of the service brake system, this may be any single failure in the
RBS.
* * * * *
S7.10.4 Performance requirements. For vehicles manufactured with a
split service brake system, in the event of any failure in a single
subsystem, as specified in S7.10.3(f) of this standard, and after
activation of the brake system indicator as specified in S5.5.1, the
remaining portions of the service brake system shall continue to
operate and shall stop the vehicle as specified in S7.10.4(a) or
S7.10.4(b). For vehicles not manufactured with a split service brake
system, in the event of any failure in any component of the service
brake system, as specified in S7.10.3(f), and after activation of the
brake system indicator as specified in S5.5.1 of this standard, the
vehicle shall, by operation of the service brake control, stop 10 times
consecutively as specified in S7.10.4(a) or S7.10.4(b).
S7.11.3. Test conditions and procedures.
* * * * *
(m) For vehicles with electrically-actuated service brakes (brake
power unit), this test is conducted with any single electrical failure
in the electrically-actuated service brakes instead of a failure of any
other brake power or brake power assist unit, and all other systems
intact.
(n) For an EV with RBS that is part of the service brake system,
this test is conducted with the RBS disconnected and all other systems
intact.
* * * * *
S7.12.2. Test conditions and procedures.
* * * * *
(i) For a vehicle equipped with mechanically-applied parking
brakes, make a single application of the parking brake control with a
force not exceeding the limits specified in S7.12.2(b). For a vehicle
using an electrically-activated parking brake, apply the parking brake
by activating the parking brake control.
* * * * *
Issued on: August 26, 1997.
Ricardo Martinez, M.D.
Administrator.
[FR Doc. 97-23318 Filed 9-4-97; 8:45 am]
BILLING CODE 4910-59-P
