For 1990-2009 cars

### Circuit Description

The SDM contains a sensing device that converts vehicle velocity changes to an electrical signal. The electrical signal is generated by the SDM and compared to a value stored in memory. When the generated signals exceed the stored values, the SDM deploys the air bags and stores a DTC in its memory.

### DTC Parameters

DTC B0051 sets when the SDM commands the inflator modules to deploy air bags. The following conditions must be met to set this DTC:

• | Ignition voltage is present at the SDM and continuous.

• | The SDM detects a frontal or side crash.

• | Crash was of sufficient force to warrant deployment of air bags.

### Action Taken

• | DTC B0051 will set.

• | The air bag telltale will be ON.

• | DTC is latched in SDM memory.

### Diagnostic Aids

Important: DTC B0051 is a latched code and can not be cleared from SDM memory.

• | Always start diagnosis of SIR DTCs with an inspection of vehicle, including its wiring and SIR components for visible damage.

• | Always replace SDMs with DTC B0051 set, only after all collision repairs have been completed.

• | Always perform the Diagnostic System Check - SIR procedure before using this chart.