Supplemental Inflatable Restraint (SIR)

CIRCUIT DESCRIPTION

The SDM contains 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 or when one of the generated signals exceeds the stored value and the front end discriminating sensor closes, the SDM will cause current to flow through the inflator modules deploying the air bags and causing DTC 51 to set.

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.

ACTION TAKEN

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

DTC WILL CLEAR WHEN

The SDM is replaced.

DTC CHART TEST DESCRIPTION

Numbers below refer to circled numbers on the diagnostic chart.

1. If inflator module(s) has not deployed, DTC 51 may have set falsely.

2. If DTC 51 has set with no signs of frontal impact, the diagnostic trouble code has set falsely.