Circuit Description
Driver frontal deployment loop is composed of the following parts:
| • | Dual Stage Inflatable Restraint Steering Wheel Module |
| • | Inflatable Restraint Steering Wheel Module Coil |
| • | Steering Wheel Module - C1 and C2 - High Control |
| • | Steering Wheel Module - C1 and C2 - Low Control |
There are 2 shorting bars used within the steering wheel module coil connector. They will short together both steering wheel module stage 1 high circuit and steering wheel module stage 1 low circuit and both steering wheel module stage 2 high circuit and steering wheel module stage 2 low circuit when the connector is disconnected. This will help to prevent unwanted deployment of the inflator module during servicing. During a frontal crash of sufficient force the inflatable restraint sensing and diagnostic module (SDM) will allow current to flow through the deployment loop in order to deploy the steering wheel module. The SDM performs continuous diagnostic tests on the deployment loops to check for proper circuit continuity and for shorts to ground or voltage. Any DTC detected will be stored in the memory.
DTC Descriptors
The diagnostic procedure supports the following DTCs:
| • | DTC B0012 Driver Frontal Deployment Loop Stage 1 |
| • | DTC B0013 Driver Frontal Deployment Loop Stage 2 |
The vehicle has DTCs including the DTC symptoms. Refer to DTC Symptom Description for DTC information.
DTC Symptom | DTC Symptom Descriptor |
|---|---|
01 | Short to battery |
02 | Short to ground |
04 | Open circuit |
0D | Resistance above threshold |
0E | Resistance below threshold |
Conditions for Running the DTC
Ignition voltage is within normal operating range.
Conditions for Setting the DTC
B0012 01 Stage 1 or B0013 01 Stage 2
The steering wheel module high and/or low circuit is short to voltage for 120 milliseconds.
B0012 02 Stage 1 or B0013 02 Stage 2
The steering wheel module high and/or low circuit is short to ground for 120 milliseconds.
B0012 04 Stage 1 or B0013 04 Stage 2
The steering wheel module high and/or low circuit is open for 120 milliseconds.
B0012 0D Stage 1 or B0013 0D Stage 2
The steering wheel module deployment loop resistance is more than 5.1 ohms for 120 milliseconds.
B0012 0E Stage 1 or B0013 0E Stage 2
The steering wheel module deployment loop resistance is less than 1.3 ohms for 120 milliseconds.
Action Taken When the DTC Sets
The SDM commands the AIR BAG indicator ON via GMLAN serial data communications.
Conditions for Clearing the DTC
| • | When conditions for the DTC to set no longer exist, use CLEAR DTC function of the scan tool to clear the DTC. |
| • | After 255 consecutive warm-up cycles without failure, the DTC will be cleared. |
Diagnostic Aids
The following may be the possible causes for the fault:
| • | Steering wheel module -- stage 1 and stage 2 - High and low control short circuit. |
| • | Steering wheel module - stage 1 and stage 2 - High or low control open circuit |
| • | Steering wheel module - stage 1 and stage 2 - High or low control is short to ground or voltage |
| • | Steering wheel module coil connector |
| • | The SDM harness connector |
| • | Steering wheel module fault |
| • | Steering wheel module coil fault |
| • | The SDM module fault |
Thoroughly inspect the wiring and connectors. Failure to do so may result in error of diagnosis and the trouble may occur again even when you replace the parts. If there is intermitting conditions, refer to Testing for Intermittent Conditions and Poor Connections .
Test Description
The following numbers are corresponding to the steps in the diagnostic table.
-
Test if the fault is caused by steering wheel module or steering wheel module coil.
-
Test to verify the set DTCs. If DTC B0012 01 or B0013 01 is set, test if the steering wheel module - stage 1 and stage 2 - high or low control is short to battery voltage. If DTC B0012 02 or B0013 02 is set, test if the steering wheel module - stage 1 and stage 2 - high or low control is short to ground. If DTC B0012 04, 0D, 0E or B0013 04, 0D, 0E is set, test if the steering wheel module - stage 1 and stage 2 - high or low control is open or high or low in resistance.
Step | Operation | Yes | No |
Schematic for Reference: SIR Schematics Connector End View Reference: SIR Connector End Views | |||
1 | Have you conducted Diagnostic System Check - Vehicle? | Go to Step 2 | |
2 |
Is there damage or corrosion in the connectors? | Go to Step 3 | Go to Step 4 |
3 |
Is the trouble corrected? | Go to Step 11 | -- |
4 |
Important: J-45289 CANdi Module must be used together with the scan tool. Does the scan tool display DTC B0012 or B0013? | Go to Step 6 | Go to Step 5 |
Does the scan tool display DTC B0012 or B0013? | Go to Step 9 | Go to Step 8 | |
6 |
Did you find and correct the condition? | Go to Step 11 | Go to Step 7 |
Do you find and correct the condition? | Go to Step 11 | Go to Step 10 | |
8 |
Have you finished the replacement? | Go to Step 11 | -- |
9 |
Have you finished the replacement? | Go to Step 11 | -- |
10 |
Have you finished the replacement? | Go to Step 11 | -- |
11 |
Does the DTC set again? | Go to Step 2 | System is OK |
