B0036

CIRCUIT DESCRIPTION
The inflatable restraint sensing and diagnostic module (SDM) monitors the inflatable restraint front end discriminating sensor circuit for front impact detection. The SDM processes the signal provided by the front end discriminating sensor to further support deployment of the air bags. The front end discriminating sensor is an input only to the SDM and does not directly cause air bag deployment. When the ignition is turned ON, the SDM performs continuous diagnostic tests on the deployment loops to check for proper circuit continuity and for shorts to ground or voltage. If a malfunction is detected, a diagnostic trouble code (DTC) will be stored.

CONDITIONS FOR RUNNING THE DTC
Ignition 1 voltage is within the normal operating voltage range.

CONDITIONS FOR SETTING THE DTC
The SDM detects the voltage at the front end discriminating sensor signal is greater than 3.65 volts for 300 milliseconds.

ACTION TAKEN WHEN THE DTC SETS
The SDM commands ON the AIR BAG indicator via Class 2 serial data.

CONDITIONS FOR CLEARING THE DTC
^ The condition responsible for setting the DTC no longer exists, and the scan tool clear DTCs function is used.
^ A history DTC will clear once 255 malfunction free ignition cycles have occurred.

DIAGNOSTIC AIDS
A broken or chafed wire in the front end discriminating sensor circuit may cause an intermittent condition to occur. Refer to Testing for Intermittent and Poor Connections in Diagnostic Aids.

TEST DESCRIPTION

Steps 1-3:

Steps 4-10:

The numbers below refer to the step numbers on the diagnostic table:
5. This step tests for a malfunctioning front end discriminating sensor.
6. This step tests for an open or high resistance in the front end discriminating sensor signal circuit.
7. This step tests for an open or high resistance in the front end discriminating sensor reference low circuit.
8. This step tests for a short to voltage in the front end discriminating sensor signal circuit.