General Motors has decided that a defect relating to vehicle safety exists in certain 2021-2022 Chevrolet Silverado 2500/3500 and 2021-2022 GMC Sierra 2500/3500 trucks.
GM first became aware of the problem in September 2021 when two 2021 GMC Sierra 2500 vehicles experienced under hood fires at the assembly plant. Both vehicles were parked outside awaiting shipment and had been exposed to heavy rainfall the day before. Using X-ray and CT scans on the vehicles showed a gap between the bolt head and brake pressure modulator valve (BPMV), indicating that the assembly had not been properly sealed to prevent water intrusion. Both vehicles had been subject to temporary production process changes that involved offline replacement of the electronic brake control module (EBCM), which is a sub-assembly of the BPMV. Analysis of the vehicles also found that the fire started in this area.
According to the defect report, bolts attaching the BPMV may have not been properly tightened, failing to create the seal between two sub-assemblies that is intended to prevent water intrusion. If water becomes trapped in the BPMV, it could result in a short circuit, which could lead to an under hood fire.
Owners of these trucks are advised to park outside and away from other structures until the recall repair is completed. Dealers will correct the problem by replacing the BPMV assembly.. GM’s number for this recall is N212349181 and the NHTSA campaign number is 21V-758.