B1153

CIRCUIT DESCRIPTION
The Inflatable Restraint Sensing And Diagnostic Module (SDM) contains a sensing device that converts vehicle velocity changes to an electrical signal. The SDM processes the generated electrical signal and compares it to a value stored in memory. When the generated signal exceeds the stored value, the SDM performs additional signal processing and compares the generated signals to signals stored in memory. When two of the generated signals exceed the stored values, the SDM will cause current to flow through the inflator modules. This deploys the air bags and causes DTC B1151 and DTC B1152 to set. DTC B1153 will set with DTC B1151 and DTC B1152 when a deployment occurs while a frontal deployment circuit malfunction is present.

CONDITIONS FOR SETTING THE DTC
The SDM detects a frontal crash, up to 30 degrees off the centerline of the vehicle, of sufficient force to warrant deployment of the frontal air bags, and a deployment circuit malfunction is present.

ACTION TAKEN WHEN THE DTC SETS
^ The SDM sets a diagnostic trouble code.
^ The SDM commands the AIR BAG warning lamp ON via Class 2 serial data.
^ The SDM records crash data.

CONDITIONS FOR CLEARING THE DTC
A scan tool CLEAR DTCs command is received by the SDM.

DIAGNOSTIC AIDS
DTC B1153 will be accompanied by another DTC (besides DTC B1151 and DTC B1152). Repair the malfunction causing the other DTCs before diagnosing DTC B1153.

TEST DESCRIPTION

Steps 1-6:

The following numbers refer to the step numbers in the diagnostic table:
2. It the inflator modules has not deployed, DTC B1 51/B1152 may have set falsely.
3. If DTC B1151/B1152 has set with no signs of impact/collision, the DTC has set falsely.