Supplemental Inflatable Restraint (SIR)

Diagnostic Chart:

Wiring Diagram:

CIRCUIT DESCRIPTION

The SDM contains a sensing device which converts vehicle velocity changes to an electrical signal. The electrical signal generated is processed by the SDM and then compared to a value stored in memory. When the generated signal exceeds the stored value, additional signal processing is performed and the generated signals are compared to signals stored in memory. When two of the generated signals exceed the stored values, the SDM will cause sufficient current to flow through the inflator modules deploying the air bags. DTC 53 is set instead of DTC 51 when a deployment occurs while an inflator circuit fault is present that could possibly result in a no deployment situation in one or both inflator modules.


DTC WILL SET WHEN:

The SDM detects a frontal crash, up to 30 degrees off the centerline of the vehicle, of sufficient force to warrant deployment of the air bags and an inflator circuit fault is present.

ACTION TAKEN:

SDM turns "ON" the "AIR BAG" indicator, records "Crash Data," and sets a diagnostic trouble code.


DTC WILL CLEAR WHEN

The SDM is replaced. If DTC 53 is set, one or more DTCs will be set in addition to DTC 5 3. Malfunction(s) setting DTC(s) (other than DTC 71) must be repaired so that DTC(s) will not be set when a new SDM is installed.


DTC CHART TEST DESCRIPTION

Number(s) below refer to circled number(s) on the diagnostic chart.

1. If inflator module(s) has not deployed, DTC 53 may have set falsely.

2. If DTC 53 has set with no signs of frontal impact, the diagnostic trouble code has set falsely.