Circuit Description
The inflatable restraint steering wheel module deployment loop consists of the inflatable restraint steering wheel module, the inflatable restraint steering wheel module coil, and the steering wheel module high and steering wheel module low circuits. A shorting bar is used in the inflatable restraint steering wheel module coil which will short the steering wheel module high and steering wheel module low circuits when the connector is disconnected. This will prevent unwanted deployment of the steering wheel module during servicing. When the ignition is turned ON, the inflatable restraint sensing and diagnostic (SDM) performs continuous diagnostic tests on the deployment loop to check for proper circuit continuity and for shorts to ground or voltage. If a malfunction is detected, the SDM will store a diagnostic trouble code (DTC).
Conditions for Running the DTC
Ignition 1 voltage is within the normal operating voltage range.
Conditions for Setting the DTC
Steering wheel module deployment loop resistance is more than 2.9 ohms for 500 milliseconds.
Action Taken When the DTC Sets
The SDM turns the AIR BAG indicator ON.
Conditions for Clearing the DTC
| • | The condition responsible for setting the DTC no longer exists and the scan tool Clear DTCs function is used. |
| • | A history DTC will clear once 255 malfunction free ignition cycles have occurred. |
Diagnostic Aids
Thoroughly inspect the wiring and the connectors. An incomplete inspection of the wiring and the connectors may result in misdiagnosis, causing a part replacement with the reappearance of the malfunction. The following are possible causes of the malfunction:
| • | The wire to terminal connections in the steering wheel module high circuit |
| • | The wire to terminal connections in the steering wheel module low circuit |
| • | The steering wheel module upper coil connector |
| • | The steering wheel module coil connector |
| • | The SDM connector |
| • | An internal SDM malfunction |
If an intermittent condition exists, refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
Test Description
The numbers below refer to step numbers on the diagnostic table.
-
Tests to see if the malfunction is intermittent.
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Tests to see if the malfunction is caused by the steering wheel module.
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Tests to see if the malfunction is caused by the steering wheel module coil.
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Tests to see if there is an open or a high resistance in the steering wheel module high or the steering wheel module low circuits.
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
SCHEMATIC REFERENCE: SIR Schematics | ||||
1 | Did you perform A Diagnostic System Check - SIR? | -- | Go to Step 2 | |
2 |
Does the steering wheel module upper coil connector exhibit any signs of damage or corrosion? | -- | Go to Step 3 | Go to Step 4 |
3 |
Did you complete the replacement? | -- | Go to Step 12 | -- |
Does the scan tool indicate that DTC 31 is current? | -- | Go to Step 5 | Go to Diagnostic Aids | |
Does the scan tool indicate that the DRIVER AIR BAG RES. is greater than the specified value? | 2.9 ohms | Go to Step 7 | Go to Step 6 | |
6 |
Did you complete the replacement? | -- | Go to Step 12 | -- |
Does the scan tool indicate that the DRIVER AIR BAG RES. is greater than the specified value? | 2.9 ohms | Go to Step 9 | Go to Step 8 | |
8 |
Did you complete the replacement? | -- | Go to Step 12 | -- |
9 |
Did you find and correct the condition? | -- | Go to Step 12 | Go to Step 10 |
Did you find and correct the condition? | -- | Go to Step 12 | Go to Step 11 | |
11 | Replace the SDM. Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement . Did you complete the replacement? | -- | Go to Step 12 | -- |
12 |
Does the DTC reset? | -- | Go to Step 2 | System OK |
