Supplemental Inflatable Restraint (SIR)

CIRCUIT DESCRIPTION
The steering column circuit consists of the driver inflator module, SRS coil assembly, center sensor assembly and associated wires. The center sensor assembly injects a small amount of current through the steering column circuit through the D+ CKT output, terminal "B3". By monitoring tile voltage at the D- CKT input, terminal "B4", the center sensor assembly calculates the combined resistance of the driver inflator module, SRS coil assembly and their associated wiring.

FAILURE CONDITIONS
DTC 13 will set if the center sensor assembly detects a shorted steering column circuit (D+ CKT shorted to D- CKT).

ACTION TAKEN
The center sensor assembly will illuminate the "AIR BAG" indicator and open the safety circuit, disabling the SRS.

TEST DESCRIPTION
Number(s) below refer to circled number(s) on the diagnostic chart.
1. This test determines whether the fault is in the steering column components or in the SRS circuitry.
2. This test determines whether the fault is due to a short from the D+ CKT to the D- CKT or a faulty center sensor assembly.
3. This test determines whether the steering column fault is due to a faulty SRS coil assembly or a faulty driver inflator module.