Supplemental Inflatable Restraint (SIR)

Diagnostic Chart:

Wiring Diagram:

CIRCUIT DESCRIPTION

When the ignition switch is turned to "RUN," the SDM will perform tests to diagnose critical malfunctions within itself. Upon passing these tests, "Ignition 1," 23 VLR, and deployment loop voltages are measured to ensure they are within their respective normal voltage ranges. The SDM then proceeds with the "Resistance Measurement Test." "Passenger Side Low" terminal "4" is grounded through a current sink and the passenger current source connected to "Passenger Side High" terminal "I" allows a known amount of current to flow. By monitoring the voltage difference between "Passenger Side High" and "Passenger Side Low," the SDM calculates the combined resistance of the passenger inflator module, harness wiring CKTs 1403 and 1404, and connector terminal contact.


DTC WILL SET WHEN:

The combined resistance of the passenger inflator module, harness wiring CKTs 1403 and 1404 and connector terminal contact is below a specified value. This test is run once each ignition cycle during the "Resistance Measurement Test" when: 1) No "higher priority faults" are detected during "Turn-ON," 2) "Ignition 1" voltage is above a specified value.


ACTION TAKEN:

SDM turns "ON" the "AIR BAG" indicator and sets a diagnostic trouble code.

DTC WILL CLEAR WHEN

The ignition switch is cycled.


DTC CHART TEST DESCRIPTION

Number(s) below refer to circled number(s) on the diagnostic chart.

1. Monitoring "Pass. Resist." after each ignition switch to "RUN" may help to locate the fault. The "Pass. Resist." value is updated each ignition switch to "RUN."

2. This test verifies proper connection of the passenger inflator module yellow 2-way connector.

3. This test checks for a malfunctioning passenger inflator module.

4. This test determines if the malfunction is due to a short between CKT 1403 and 1404.

5. This test determines if the malfunction is due to a short between CKT 1403 and 348.


DIAGNOSTIC AIDS

An intermittent condition is likely to be caused by a short between CKT 1403 and CKT 347, CKT 348 or CKT 1404, or a malfunctioning shorting bar on the passenger inflator module which would require replacement of the passenger inflator module. The test for this diagnostic trouble code is only run while the "AIR BAG" indicator is performing the "BULB TEST." 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.