01-20667. General Motors Corporation; Denial of Application for Determination of Inconsequential Noncompliance

General Motors Corporation (GM) has determined that seat belt assemblies in certain 1999-2000 Model Year Chevrolet S-10 and GMC Sonoma pickup trucks and Chevrolet Blazer/Trail Blazer, GMC Jimmy/ Envoy, and Oldsmobile Bravada sport utility vehicles failed to comply with the requirements of Federal Motor Vehicle Safety Standard (FMVSS) No. 209 “Seat Belt Assemblies,” and filed an appropriate report pursuant to 49 CFR part 573, “Defect and Noncompliance Information Reports.” GM also applied to be exempted from the notification and remedy requirements of 49 U.S.C. 30118—30120 on the basis that the noncompliance is inconsequential to motor vehicle safety. See 49 U.S.C. 30118(d) and 30120(h).

Notice of receipt of the application was published on April 25, 2000, and an opportunity afforded for comment (65 FR 24252). This notice denies the application.

According to GM, from November 1998 through August 1999, the company manufactured approximately 463,513 1999 and 2000 model year Chevrolet S-10 and GMC Sonoma pickup trucks and the Chevrolet Blazer/Trail Blazer, GMC Jimmy/Envoy, and Oldsmobile Bravada sport utility vehicles that failed the performance requirement of S4.3(j)(1) of FMVSS No. 209 which states, “* * * Shall lock before the webbing extends 25 mm when the retractor is subjected to an acceleration of 7 m/s² (0.7g) . . .”

GM stated that the noncompliance results from a plastic flash (burr) on the mechanical sensor lever near its pivot where it mates to the sensor housing. This flash can cause a nonconformance to the 0.7 g locking requirement due to potential increased drag of the sensor lever in the housing. GM believes that only a very small portion of the subject retractors fail to meet the 0.7 g retractor locking requirement and the transportation shock and vibration that the subject retractors might experience during transit to dealerships, either by rail or truck (haulaway), would make compliant a large percentage of the noncompliant retractors.

GM stated that the subject seat belt assemblies locked at no more than 1.2 g. GM provided dynamic frontal barrier test data demonstrating that onset shoulder belt loading occurs prior to the time it takes for the seat belt assembly to reach 1.2 g. In addition, GM calculated the acceleration to lock the retractor in a rollover simulation and concluded that the subject retractors will lock up prior to rollover.

No responses were received on the request for public comments.

The purpose of the emergency locking retractor (ELR) requirement is to lock the webbing spool and restrain an occupant's travel distance before the occupant strikes the vehicle's interior structure during panic braking to avoid death and injury. In establishing the levels for the ELR requirement, in response to the March 17, 1970 Notice of Proposed Rulemaking (NPRM) to amend S4.3(j)(1) of FMVSS No. 209 GM stated,

“General Motors believes that emergency locking retractors should lock during panic braking maneuvers if optimum performance is to be expected from an upper torso restraint system that is equipped with such retractors. During panic braking, an occupant may be subjected to deceleration forces well under 1.0 gravity. These decelerations usually cause the occupant to move relative to the vehicle unless restrained. In many instances, vehicle impacts are immediately preceded by panic braking which may cause the restraint system to become fully extended prior to impact unless the retractor can lock at values under 1.0 gravity. In order to balance the convenient use of the system with the necessity to have it perform its safety restraint function, General Motors believes the standard should require that an emergency locking retractor should not lock below 0.3 gravity but must lock above 0.7 gravity.” (35 FR 4641)

The subject ELRs locked at levels as high as 1.2 g, which is not the “optimum performance * * * expected from an upper torso restraint system,” which currently is required at 0.7 g, as recommended by GM in their response to the 1970 NPRM. GM determined by its dynamic frontal barrier test data that onset shoulder belt loading occurs prior to the time it takes for the seat belt assembly to reach 1.2 g. NHTSA shares the same concern GM had in its 1970 NPRM response that,

“during panic braking, an occupant may be subjected to deceleration forces well under 1.0 gravity. These decelerations usually cause the occupant to move relative to the vehicle unless restrained. In many instances, vehicle impacts are immediately preceded by panic braking which may cause the restraint system to become fully extended prior to impact unless the retractor can lock at values under 1.0 gravity.”

Since these subject retractors do not lock at deceleration forces below 1.0 g, but instead lock up at 1.2 g, the delay in lockup time may cause occupants to move about more freely in a frontal crash or in a rollover, and thus be injured by striking the interior of the vehicle. The injury potential may apply more so to those who sit in a full forward seating position, or close to an object such as the steering wheel, the knee bolster, or other parts of the interior of the vehicle. GM did not provide any dynamic frontal crash injury criteria data to disprove the delay in lockup might not cause injury to an occupant with these noncompliant retractors.

GM believes that the pre-sale delivery transportation shock and vibration that the subject retractors might experience during transit to dealerships, either by rail or truck (haulaway), would jar a lot of the burrs off of these parts and make compliant a large percentage of the noncompliant retractors. However, GM admits that some noncompliant retractors will remain and a safety risk will still exist.

In order for NHTSA to decide an inconsequentiality petition, it is necessary to determine whether the particular noncompliance is likely to increase the risk that an occupant will experience the type of injury that the requirement is intended to prevent. Arguments that only a small number of vehicles or pieces of motor vehicle equipment are affected generally will not justify granting a petition. But, more importantly, the key issue is whether the noncompliance is likely to increase the safety risk to occupants. Cosco, Inc.; Denial of Application for Inconsequential Noncompliance, 64 FR 29408 (June 1, 1999). In this instance, we conclude that the noncompliance is likely to increase a safety risk to users of the restraint system.

In consideration of the foregoing, it is hereby found that the applicant has failed to meet its burden of persuasion that the noncompliance herein described is inconsequential to safety, and its application is denied.

(49 U.S.C. 30118, 30120; delegations of authority at 49 CFR 1.50 and 49 CFR 501.8)

Issued on: August 13, 2001.

Stephen R. Kratzke,

Associate Administrator for Safety Performance Standards.