Circuit Description
When the ignition switch is first turned ON, Ignition 1 voltage is applied from the GAUGES fuse to Redundant Indicator Ignition 1, terminal B2, and to the AIR BAG warning lamp which is connected to SIR Indicator, terminal B1. The AIR BAG fuse applies system voltage to the Ignition 1 inputs, terminals A9 and A10. The inflatable restraint Diagnostic Energy Reserve Module (DERM) Responds by flashing the AIR BAG warning lamp seven times. If Ignition 1 is outside of the normal operating voltage range, the AIR BAG warning lamp come on solid with no DTC set.
When the engine is being cranked, Ignition 1 voltage is applied from the CRANK fuse to the DERM at the Crank input. The DERM responds by grounding the SIR Indicator output until Ignition 1 voltage is removed from the Crank input. This results in the AIR BAG warning lamp being on during cranking.
After cranking, the DERM will flash the AIR BAG warning lamp six times.
Test Description
Refer to step numbers on the diagnostic table.
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Start at the SIR Diagnostic System Check for all diagnosis.
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An open AIR BAG fuse would cause the AIR BAG warning lamp to come on steady.
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A disconnected DERM harness connector will cause the warning lamp to come on steady via the shorting bar from terminal A1 to terminal B1.
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This test checks for a open in the ground circuitry to the DERM.
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This test checks for an open in the Ignition 1 circuitry to the DERM.
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This test checks for a short from the Crank input to circuit to B+.
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This test determines where the short-to-voltage is located in circuit 806/1035.
When measurements are requested in this table use J 39200 Digital Multimeter with correct terminal adapter from J 35616 Connector Test Adapter Kit. When a check for proper connection is requested, refer to Intermittents and Poor Connections in Section 8A4. When a wire, connector or terminal repair is requested, use J-38125 Terminal Repair Kit and refer to Wiring Repair.
Step | Action | Value | Yes | No |
|---|---|---|---|---|
Was the SIR Diagnostic System Check performed? | -- | |||
Is the fuse good? | -- | |||
Inspect the DERM electrical harness connector connection to the DERM. Is the connector securely connected to the DERM? | -- | |||
4 |
Are the connector terminals damaged or corroded? | -- | ||
5 | Check for proper connection to the DERM at terminals A1, A9, A10, A12. Are the DERM terminals damaged or corroded? | -- | ||
6 | Repair the DERM electrical harness connector. Has the connector been repaired? | -- | -- | |
7 | Check for proper connection to the DERM at terminals A1, A9, A10, A12. Are the DERM terminals damaged or corroded? | -- | ||
8 | Replace to DERM. Refer to Inflatable Restraint Diagnostic Energy Reserve Module . Has the DERM been replaced? | -- | -- | |
9 | Measure the resistance from the DERM harness connector terminal A1 to a known good ground. Is the resistance less than the value specified? | 5 ohms | ||
10 | Repair the open in the circuit 1751. Has the open been repaired? | -- | -- | |
Measure the resistance from each terminal of the AIR BAG fuseholder to the DERM electrical harness connector terminal A9 and A10. Is either resistance less than the specified value? | 5 ohms | |||
12 |
Does the AIR BAG warning lamp come ON? | -- | ||
13 |
Does the AIR BAG warning lamp come ON? | -- | ||
14 |
Has the short circuit been repaired? | -- | -- | |
15 |
Has the short circuit been repaired? | -- | -- | |
Is the voltage less than the value specified? | 1 V | Go to Integrity Check | ||
Is the voltage less than the value specified? | 1 V | |||
18 |
Has the short circuit been repaired? | -- | -- | |
19 |
Has the short circuit been repaired? | -- | -- | |
20 |
Is the fuse good? | -- | ||
21 |
Is the fuse good? | -- | ||
22 | Replace the inflatable restraint arming sensor. Refer to Inflatable Restraint Arming Sensor . Has the sensor been replaced? | -- | -- | |
23 | Repair the short-to-ground in circuit 1139. Has the short circuit been repaired? | -- | -- | |
24 | Properly connect the DERM electrical harness connector to the DERM. Has the connector been properly connected to the DERM? | -- | -- | |
25 |
Is the connector damaged or corroded? | -- | ||
26 | Repair electrical connector C200 terminal S. Has the connector been repaired? | -- | -- | |
27 |
Is the voltage about to equal the value specified? | 12 V | ||
28 | Repair the open in circuit 1139 between C200 terminal S and terminal A9 and A10 of the DERM module. Has the open circuit been repaired? | -- | -- | |
29 | Repair the open in circuit 1139 between C200 terminal S and the AIR BAG fuse. Has the open circuit been repaired? | -- | -- | |
30 |
Have all the SIR components been reconnected and properly mounted? | -- | -- | |
31 | Clear the SIR Diagnostic Trouble Codes? Have the SIR Diagnostic Trouble Codes been cleared? | -- | -- |
