Supplemental Inflatable Restraint (SIR)

Diagnostic Chart:

Wiring Diagram:

CIRCUIT DESCRIPTION
During the "Initiator Assembly Resistance Test" the DERM grounds the "Passenger Side Low" terminal "B7" and turns "ON" the driver current source at the "Driver Side High" terminal "B9." The DERM then grounds the "Driver Side Low" terminal "B8" and turns "ON" the passenger current source at the "Passenger Side High" terminal "A7." During each of these tests the DERM monitors voltage at "Driver Side Low," "Passenger Side Low," the difference between "Driver Side High" and "Driver Side Low" and the difference between "Passenger Side High" and "Passenger Side Low." When the measured values are outside the expected range DTC 28 is set.

DTC WILL SET WHEN
The voltage measured at "Driver Side Low" or "Passenger Side Low" is below a specified value while its respective initiator resistance is in range or when the voltage measured at "Driver Side Low" or "Passenger Side Low" is above a specified value. This test is run once each ignition cycle during the "Initiator Assembly Resistance Test" when: 1) No "higher priority faults" are detected during "Turn-ON," 2)No "higher priority faults" are detected during "Continuous Monitoring" for one second, 3) No "Crank" signal present, 4) "Ignition 1" voltage is above a specified value.

ACTION TAKEN
DERM sets a diagnostic trouble code and sends a command to the instrument cluster to turn "ON" the "AIR BAG" warning lamp.

DTC WILL CLEAR WHEN
The ignition switch is turned "OFF."

DTC CHART TEST DESCRIPTION
Number(s) below refer to circled number(s) on the diagnostic chart.
1. This test checks for a high resistance between the passenger inflator module jumper and the passenger compartment discriminating sensor.
2. This test checks for a high resistance in the discriminating sensor interconnect circuit.
3. This test checks for a high resistance between the steering column harness connector and the forward discriminating sensor.

DIAGNOSTIC AIDS
An intermittent condition is likely to be caused by a poor connection to passenger compartment discriminating sensor terminal "E," forward discriminating sensor terminal "A" or poor wire to terminal connection in CKT 348B, CKT 349 or CKT 1404C. When a scan tool "Clear Codes" command is issued and the malfunction is still present, the DTC will not reappear for ten minutes or until the next ignition cycle.