Chart A History Code Diagnosis

Diagnostic Chart:

Wiring Diagram:

CIRCUIT DESCRIPTION

When the DERM recognizes "Ignition 1" voltage, applied to terminal "A9" and "A10", is in the normal operating voltage range, the "AIR BAG" warning lamp is flashed 7 times to verify operation. At this time the DERM performs "Turn-ON" tests followed by "Continuous Monitoring" tests. When no malfunctions are detected the DERM proceeds to the "Initiator Assembly Resistance Test." When a malfunction is detected the DERM sets a current diagnostic trouble code and illuminates the "AIR BAG" warning lamp. The DERM will clear current diagnostic trouble codes and move them to a history file when the malfunction is no longer detected and/or the ignition switch is cycled, except for DTC 51. DTC 51 can only be cleared using a scan tool "Clear Codes" command.

TEST DESCRIPTION

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

1. Since performing the "SIR Diagnostic System Check" properly ensures correct operation of the "AIR BAG" warning lamp, no malfunction is indicated.

2. Checks for opens in the high side of the deployment loops or shorts to ground in the low side of the deployment loops.

3. Checks for shorts to B + in the deployment loops.

4. Checks for an improperly connected dual pole arming sensor.

5. Checks for an open in the "Ignition 1" feed to the deployment loops.

6. Checks for a condition which would prevent either "36 VLR" power supply from fully charging.

7. Checks for conditions which the DERM interprets as an open in the "Driver 36 VLR" circuit.

8. Checks for conditions which the DERM interprets as an open in the" Passenger 36 VLR" circuit.

9. Check for an open or high resistance in the driver inflator module circuitry.

10. Checks for an open or high resistance in the passenger inflator module circuitry.

11. Checks for shorts which would cause the resistance of the inflator modules measured by the DERM to be too low.

12. Checks for an open in CKT 1404C.

13. Checks for an open in CKT 348A.

14. Checks for shorts from the "36 VLR" circuits to diagnostic circuits or a short which decreases the effective resistance at the high side of the deployment loops.

15. Checks for shorts which the DERM interprets as an open driver ignition diode.

16. Checks for shorts which the DERM interprets as an open passenger ignition diode.

17. Checks for improper connections to the discriminating sensors.

18. Checks for improper connections to the LH forward discriminating sensor.

19. Checks for an open or short to ground in the "Driver Source Sense" circuit.

20. Checks for an open or short to ground in the "Passenger Source Sense" circuit.

21. Checks for an open in the "Driver Side Low" circuit.

22. Checks for an open in the "Passenger Side Low" circuit.