Chevy Air Bag Mystery
This bulletin applies to 2007-2010 Chevy Avalanche 2WD models. Some customers may experience an SIR (Supplemental Inflatable Restraint) lamp. The technician may find a history or current DTC B1019, with a symptom code 3A.
If the SDM (Sensing Diagnostic Module) has been replaced or programmed prior to this condition, make sure that the SDM has been programmed correctly with the correct options before performing any of the diagnostics listed here.
1. Inspect the operation of the passenger air bag on/off indicator and the passenger’s seat belt indicator that is located in the overhead console.
2. If a concern is noticed with the passenger seat belt indicator, locate the proper seat belt schematic and inspect circuit 5234 going from the IPC to the passenger air bag on/off indicator assembly. Also inspect for the proper power feed to the passenger air bag on/off indicator assembly.
3. Most concerns in the field are caused by a connector that is not fully seated in the left IP junction block, a short on circuit 5234 at the park brake pedal assembly or connection at the overhead center console assembly.
4. If the concern can be duplicated and the SDM is setting a current code B1019 Sym 3A and all three indicators are working properly, try a known good IPC and/or replace the IPC as needed.
Note that on some models, DTC B1019 3A will not turn on the SIR MIL or message.