Circuit Description
When the ignition switch is first turned to RUN, the GAUGES Fuse applies battery voltage to the AIR BAG warning lamp that is connected to Air Bag Indicator Control, terminal 7. The AIR BAG Fuse applies battery voltage to the IGNITION 1 input, terminal 10. The inflatable restraint Sensing and Diagnostic Module (SDM) responds by flashing the AIR BAG warning lamp seven times. If IGNITION 1 is outside of the normal operating voltage range (8.2 volts - 17.1 volts), the AIR BAG warning lamp will come ON solid with no DTCs set.
Diagnostic Aids
In order to disable the shorting bar from terminal 6 to terminal 7 inside the inflatable restraint Sensing and Diagnostic Module (SDM) harness connector, the following two conditions must be met:
| • | The SDM harness connector must be properly connected to the SDM. |
| • | The Connector Position Assurance (CPA) must be properly installed in the SDM harness connector. |
When measurements are requested in this table, use the J 39200 DMM with the correct terminal adapter from the J 35616 Connector Test Adapter Kit. When an inspection for proper connection is requested, refer to Testing for Electrical Intermittents in Wiring Systems. When a wire, connector or terminal repair is requested, use the J-38125 Terminal Repair Kit and refer to Wiring Repairs in Wiring Systems.
Test Description
The numbers below refer to the step numbers on the diagnostic table:
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This test checks for sufficient IGNITION 1 voltage applied to the SDM.
-
This test checks for excessive IGNITION 1 voltage applied to the SDM.
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This test checks for a properly installed CPA.
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This test determines if the SDM is turning on the AIR BAG warning lamp.
-
This test checks for a damaged shorting bar.
-
This test determines whether the malfunction is a short to ground in CKT 358.
-
This test checks for a short between CKTs 358 and 1751.
-
An open Air Bag Fuse would cause the AIR BAG warning lamp to come on steady.
-
This test checks whether a short to ground caused the Air Bag Fuse to open.
-
This test determines whether the short to ground is due to a short in the wiring or internal to the SDM.
-
This test determines whether the short to ground is due to a short in the wiring or internal to the inflatable restraint IP module switch.
-
This test checks for a disconnected SDM.
-
This test checks for an open in the IGNITION 1 circuit.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
1 | Was the SIR Diagnostic System Check performed? | -- | ||
Is IGNITION more than the specified value? | 8.2 V | |||
Is IGNITION more than the specified value? | 17.1 V | Go to Charging System Check | ||
Is the CPA properly installed? | -- | |||
5 | Properly install the CPA. Are the repairs complete? | -- | -- | |
Does the AIR BAG warning lamp come ON steady? | -- | |||
Is the shorting bar damaged or corroded? | -- | |||
8 | Replace the SDM harness connector. Are the repairs complete? | -- | -- | |
9 |
Is the shorting bar damaged or corroded? | -- | ||
10 | Replace the IP harness side of connector C232. Refer to Wiring Repair Has the IP harness side of connector C232 been replaced? | -- | -- | |
11 | Check for proper connection at terminals A1 and A2 on the IP harness side of connector C232. Are the terminals damaged or corroded? | -- | ||
12 | Replace the IP harness side of connector C232. Has the IP harness side of connector been replaced? | -- | -- | |
13 | Check for proper connection at terminals A1 and A2 on the harness side of connector C232. Are the terminals damaged or corroded? | -- | ||
14 | Replace the harness side of connector C232. Has the harness side of connector C232 been replaced? | -- | -- | |
Is the resistance reading less than the specified value? | OL | |||
Is the resistance reading less than the specified value? | OL | |||
17 | Repair a short to ground condition in CKT 358. Are the repairs complete? | -- | -- | |
18 |
Are the repairs complete? | -- | -- | |
19 | Service the instrument cluster. Refer to Instrument Cluster Replacement in Instrument Panel And Gauges. Are the repairs complete? | -- | -- | |
Is the Air Bag Fuse good? | -- | |||
Is the Air Bag Fuse good? | -- | |||
Is the Air Bag Fuse good? | -- | |||
23 | Does this vehicle have a inflatable restraint IP module switch? | -- | ||
Is the Air Bag Fuse good? | -- | |||
25 |
Has the inflatable restraint IP module switch been replaced and the Air Bag Fuse installed? | -- | -- | |
26 |
Are the repairs complete? | -- | -- | |
27 |
Are the repairs complete? | -- | -- | |
28 | Install the Air Bag Fuse. Are the repairs complete? | -- | -- | |
Inspect the SDM harness connector. Is the connector securely connected to the SDM? | -- | |||
30 |
Are the repairs complete? | -- | -- | |
31 |
Is the SDM harness connector terminal damaged or corroded? | -- | ||
32 | Replace the SDM harness connector. Refer to Wiring Repair . Are the repairs complete? | -- | -- | |
33 | Inspect the SDM terminals for damage or corrosion. Are any terminals damaged or corroded? | -- | ||
34 | Replace the SDM. Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement . Are the repairs complete? | -- | -- | |
Measure the resistance from the SDM harness connector terminal 10 to each terminal of the Air Bag Fuse fuse holder. Is either resistance reading within the specified values? | 0-5 ohms | |||
36 | Repair an open condition in CKT 1139. Are the repairs complete? | -- | -- | |
37 | Reconnect all the SIR system components, make sure all the components are properly mounted. Have all the SIR components been reconnected and properly mounted? | -- | -- |
