Supplemental Inflatable Restraint (SIR)

Diagnostic Chart:

Circuit Schematic:

CIRCUIT DESCRIPTION
When the ignition switch is turned On, the Sensing & Diagnostics Module (SDM) will perform tests to diagnose critical malfunctions within itself. Upon passing these tests "Ignition 1," 36 VLR (Voltage Loop Energy Reserve), and deployment loop voltages are measured to ensure they are within their respective normal voltage ranges. The ADM then proceeds with the "Current Source Diagnostics." "Passenger Side Low" terminal A6 is grounded through a resistor and the passenger current source connected to "Passenger Side High" terminal A5 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 circuits 1403 and 1404 and connector terminal contact.

DTC WILL SET WHEN:
The combined resistance of the passenger inflator module, harness wiring circuits 1403 and 1404, and connector terminal contact is above a specified value. This test is run once each ignition cycle during the "Current Source Diagnostic" when:
1. No "higher priority faults" are detected during "Turn-On,"
2. No "higher priority faults" are detected during "Continuous Monitoring,"
3. "Ignition 1" voltage is above a specified value.

ACTION TAKEN:
SDM turns On the AIR BAG warning lamp and sets a diagnostic trouble code.

DTC WILL CLEAR WHEN:
The ignition switch is turned Off.

DTC CHART TEST DESCRIPTION:
Number(s) below refer to step 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 passenger inflator module circuitry or in the SDM wiring harness circuitry.

4. This test checks for a short from the "Passenger Side High" circuit to the "Passenger Side Low" circuit.

6. This test checks for a short from the "Passenger Side High" circuit to the "Driver Side Low" circuit.

DIAGNOSTIC AIDS:
An intermittent condition is likely to be caused by a short between circuit 1404 and circuit 347, 348, or 1403, or a malfunctioning shorting bar on the passenger inflator module which would require replacement of the module. The test for this diagnostic trouble code is only run while AIR BAG warning lamp is performing the bulb check, unless DTC 17 or 26 is detected. When a Saturn Portable Diagnostic (Scan) (PDT) Tool "Clear Codes" command is issued and the malfunction is still present, the DTC will not reappear until the next ignition cycle.


Was the "SIR Diagnostic System Check" performed?

When measurements are requested in this chart, use (Saturn Tool) SA 91114NE DVM with correct terminal adapter from SA 9206Z.