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." This causes a known amount of current to flow through the driver initiator circuit. By monitoring the difference between the voltage at the "Driver Side High" terminal "B9" and the "Driver Side Low" terminal "B8" the DERM calculates the combined resistance of the driver inflator module, SIR coil assembly, harness wiring CKTs 347A and 348A and connector terminal contact.

DTC WILL SET WHEN
The combined resistance of the driver inflator module, SIR coil assembly, harness wiring CKTs 347 and 348 and connector terminal contact is below a specified value. This test is run 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. DTC 16 and 22 will set simultaneously when the "Driver Side High" circuit is shorted to the "Passenger Side High" circuit due to parallel current paths.
2. This test determines whether the malfunction is in the driver inflator module circuitry or in the DERM wiring harness circuitry.
3. This test checks for a short from the "Driver Side High" circuit to the "Driver Side Low" circuit and the "Passenger Side Low" circuit.
4. This test determines whether the malfunction is in the driver inflator module or the SIR coil assembly.

DIAGNOSTIC AIDS
An intermittent condition is likely to be caused by a short between CKT 347 and CKT 348, CKT 1403 or CKT 1404, a malfunctioning SIR coil assembly or a malfunctioning driver inflator module. The test for this diagnostic trouble code is only run while the "AIR BAG" warning lamp is performing the bulb check. When a scan tool "Clear Codes" command is issued and the malfunction is still present, the DTC will not reappear until the next ignition cycle.