— The National Highway Traffic Safety Administration opened an investigation into illuminated airbag warning lights and incidents of crashes where the airbags failed to deploy.
Included in the April 2021 GM airbag investigation are nearly 750,000 of these vehicles:
- 2020-2021 Chevrolet Silverado
- 2020-2021 Chevrolet Tahoe
- 2020-2021 Chevrolet Suburban
- 2020-2021 GMC Sierra
- 2020-2021 GMC Yukon
- 2020-2021 GMC Yukon XL
- 2020-2021 Cadillac Escalade
- 2020-2021 Cadillac Escalade ESV
- 2020-2021 Cadillac CT4
- 2020-2021 Cadillac CT5
- 2020-2021 Cadillac XT4
The month before NHTSA opened the investigation, General Motors issued technical service bulletin 21-NA-005 regarding illuminated airbag warning lights with diagnostic trouble codes (DTCs) B0001-1B or B0012-0D.
The TSB told GM dealers rust particles in the connection terminal interface of the driver airbag inflator housing could cause the airbag warning lights to stay on. This could also result in non-deployment of the frontal driver airbag during a frontal collision.
"GM stated a correlation exists between production delays due to the pandemic shutdown and premature corrosion initiation on the surface of the air bag inflator housing, which, in some cases, caused rust development during a seven (7) month period of vehicle production." — NHTSA
NHTSA found it was rare, but a rust particle could dislodge from the airbag inflator housing and enter the airbag connector before the airbags were assembled. If this occurs, an electrical resistance spike can result when the horn is used or when the steering wheel is turned.
Safety regulators found a crash commanding airbag deployment would need to occur exactly when the momentary excessive resistance occurs.
Although injuries had been alleged, NHTSA closed the GM airbag warning light investigation because there have been no reported fires, crashes, injuries or fatalities related to this problem.
"In view of the low rate, and the nature of early-life failure, the high detectability of failures, and low potential hazard to drivers, this Preliminary Evaluation (PE) is closed." — NHTSA
