The inflatable restraint steering wheel module deployment loop consists of the inflatable restraint steering wheel module, the inflatable restraint steering wheel module coil, the steering wheel module high circuit, and the steering wheel module low circuit. A shorting bar is used in the inflatable restraint steering wheel module coil connector, 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 module (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).
Ignition 1 voltage is within the normal operating voltage range.
The DTC will set if one of the following conditions occurs:
• | Steering wheel module high circuit is less than 2.4 volts and the steering wheel module deployment loop resistance is more than 6 ohms for 500 milliseconds during the deployment loop voltage out of range test. |
• | Steering wheel module deployment loop resistance is more than 4.8 ohms for 500 milliseconds during the deployment loop resistance measurement test. |
The SDM commands the AIR BAG indicator ON via Class 2 serial data.
• | The condition responsible for setting the DTC no longer exists and the scan tool Clear DTC's function is used. |
• | A history DTC will clear once 255 malfunction free ignition cycles have occurred. |
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 malfunction exists, refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
The number(s) below refer to the step number(s) on the diagnostic table.
Tests to see if the malfunction is intermittent
Tests to see if the malfunction is caused by the steering wheel module or the steering wheel module coil
Tests to see if there is an open or a high resistance in the steering wheel module high or steering wheel module low circuits
Step | Action | Yes | No |
---|---|---|---|
Schematic Reference: SIR Schematics | |||
1 | Did you perform the Diagnostic System Check - SIR? | Go to Step 2 | |
2 |
Does steering wheel module coil connector exhibit any signs of damage or corrosion? | Go to Step 3 | Go to Step 4 |
3 |
Did you complete the repair? | Go to Step 12 | -- |
Does the scan tool indicate that DTC B0026 is current? | Go to Step 5 | Go to Diagnostic Aids | |
5 |
Does the scan tool indicate that DTC B0026 is current? | Go to Step 9 | Go to Step 6 |
Does the scan tool indicate that DTC B0026 is current? | Go to Step 8 | Go to Step 7 | |
7 |
Did you complete the replacement? | Go to Step 12 | -- |
8 |
Did you complete the replacement? | Go to Step 12 | -- |
9 |
Did you find and correct the problem? | Go to Step 12 | Go to Step 10 |
Test the steering wheel module high and steering wheel module low circuits for an open or a high resistance. Refer to Circuit Testing and Connector Repairs in Wiring Systems. 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 |