Circuit Description
The driver frontal deployment loop consists of the following components:
| • | A dual stage inflatable restraint steering wheel module |
| • | The inflatable restraint steering wheel module coil |
| • | The steering wheel module high circuits for both stages 1 and 2 |
| • | The steering wheel module low circuits for both stages 1 and 2 |
There are 2 shorting bars used within the steering wheel module coil connector which 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. If a malfunction is detected, a diagnostic trouble code (DTC) will be stored in memory.
DTC Descriptors
This diagnostic procedure supports the following DTCs:
| • | DTC B0012 Driver Frontal Deployment Loop Stage 1 |
| • | DTC B0013 Driver Frontal Deployment Loop Stage 2 |
This vehicle has DTCs which include DTC symptoms. For more information on DTC symptoms, refer to DTC Symptom Description in Vehicle 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 the normal operating voltage 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.
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
The following are possible causes of the malfunction:
| • | A short between the steering wheel module stage 1 or stage 2, high and low circuits |
| • | An open or a high resistance in the steering wheel module stage 1 or stage 2, high or low circuits |
| • | A short to ground or a short to voltage in the steering wheel module stage 1 or stage 2, high or low circuits |
| • | The steering wheel module coil connector |
| • | The SDM connector |
| • | A malfunctioning steering wheel module |
| • | A malfunctioning steering wheel module coil |
| • | A malfunctioning SDM |
Thoroughly inspect the wiring and the connectors. An incomplete inspection of the wiring and the connectors may result in a misdiagnosis, causing a part replacement with the reappearance of the malfunction. If an intermittent malfunction exists, refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
Tests to see if the malfunction is caused by the steering wheel module or by the steering wheel module coil.
-
Tests to see what DTCs are present. If DTC B0012 01 or B0013 01 is present, test the steering wheel module for a short to battery voltage on the high and low circuits in stage 1 or stage 2. If DTC B0012 02 or B0013 02 is present, test the steering wheel module for a short to ground on the high and low circuits in stage 1 or stage 2. If DTC B0012 04, 0D, 0E or B0013 04, 0D, 0E is present, test the high and low circuits for an open circuit and for high or low resistance in stage 1 or stage 2.
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: SIR Schematics Connector End View Reference: SIR Connector End Views | |||
1 | Did you perform the Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information |
2 |
Does connector exhibits any signs of damage or corrosion? | Go to Step 3 | Go to Step 4 |
3 |
Did you complete the repair? | Go to Step 11 | -- |
4 |
Important: J-45289 CANdi module must be used with the scan tool. Does the scan tool indicate that DTC B0012 or B0013 are current? | Go to Step 6 | Go to Step 5 |
Does the scan tool indicate that DTC B0012 or B0013 are current? | Go to Step 9 | Go to Step 8 | |
6 |
Did you find and correct the condition? | Go to Step 11 | Go to Step 7 |
Did you find and correct the condition? | Go to Step 11 | Go to Step 10 | |
8 |
Did you complete the replacement? | Go to Step 11 | -- |
9 |
Did you complete the replacement? | Go to Step 11 | -- |
10 |
Did you complete the replacement? | Go to Step 11 | -- |
11 |
Does the DTC reset? | Go to Step 2 | System OK |
