GM Service Manual Online
For 1990-2009 cars only

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 .

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

Important: This code will set if the steering wheel module coil was serviced and the connector position assurance (CPA) is not inserted completely into the connector on the back side of steering wheel module coil.

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 MIL/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 .

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. This step tests to see if the malfunction is caused by the steering wheel module or by the steering wheel module coil.

  2. This step tests to see if the steering wheel module coil or by the steering wheel module coil in line connector located behind the steering wheel module coil.

  3. This step 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

2

  1. Turn OFF the ignition.
  2. Disconnect the steering wheel module coil inline connector. Refer to Inflatable Restraint Steering Wheel Module Coil Replacement .
  3. Inspect the component and harness sides of the inline connector for the steering wheel module coil for damage or corrosion that may cause the malfunction. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Does the connector exhibit any signs of damage or corrosion?

Go to Step 3

Go to Step 4

3

  1. If the inline connector for the steering wheel module coil is damaged, the steering wheel module coil must be replaced. Refer to Inflatable Restraint Steering Wheel Module Coil Replacement .
  2. If the wiring harness side of steering wheel module coil inline connector is damaged, replace the harness side of the connector. Refer to Connector Repairs .

Did you complete the repair?

Go to Step 12

--

4

  1. Connect the J 38715-A SIR Driver/Passenger Load Tool to the harness side of the steering wheel module coil connector. Use STEERING COLUMN and PASSENGER INFLATOR connectors.
  2. Turn ON the ignition, with the engine OFF.
  3. Important: The J-45289 CANdi Module must be used with the scan tool.

  4. Install a scan tool, request the SIR DTC display.

Does the scan tool indicate that DTC B0012 or B0013 are current?

Go to Step 7

Go to Step 5

5

  1. Turn OFF the ignition.
  2. Disconnect and remove both the J 38715-A and adapter.
  3. Connect the steering wheel module coil inline connector.
  4. Remove the steering wheel module. Refer to Inflatable Restraint Steering Wheel Module Replacement .
  5. Connect the J 38715-A to the upper steering wheel module coil connector on top of the steering column. Use STEERING COLUMN and PASSENGER INFLATOR connectors.
  6. Turn ON the ignition, with the engine OFF.
  7. Use the scan tool to request SIR DTCs displayed.

Does the scan tool indicate that DTC B0012 or B0013 are current?

Go to Step 6

Go to Step 9

6

  1. Turn OFF the ignition.
  2. Disconnect and remove both the J 38715-A and adapter.
  3. Remove the steering column trims covers. Refer to Steering Column Trim Covers Replacement .
  4. Disconnect the steering wheel module coil inline connector, located behind the steering wheel module coil.
  5. Connect the J 38715-A to the harness side of the steering wheel module coil connector. Use BASE OF COLUMN and PASSENGER INFLATOR connectors.
  6. Turn ON the ignition, with the engine OFF.

Does the scan tool indicate that DTC B0012 or B0013 are current?

Go to Step 8

Go to Step 10

7

  1. Turn OFF the ignition.
  2. Disconnect and remove both the J 38715-A and adapter.
  3. Disconnect the inflatable restraint sensing and diagnostic module (SDM) connector. Refer to Control Module References for replacement, setup, and programming.
  4. Inspect the SDM connector for damage or corrosion that may cause a malfunction in the steering wheel module stage 1 or stage 2 high and/or low circuits. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 12

Go to Step 8

8

  1. 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.
  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.
  3. 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.
  4. For all the above conditions, refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 12

Go to Step 11

9

  1. Turn OFF the ignition.
  2. Replace the steering wheel module. Refer to Inflatable Restraint Steering Wheel Module Replacement .

Did you complete the replacement?

Go to Step 12

--

10

  1. Turn OFF the ignition.
  2. Replace the steering wheel module coil. Refer to Inflatable Restraint Steering Wheel Module Coil Replacement .

Did you complete the replacement?

Go to Step 12

--

11

  1. Turn OFF the ignition.
  2. Replace the SDM. Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 12

--

12

  1. Connect all SIR components and connectors.
  2. Turn ON the ignition, with the engine OFF.
  3. Use the scan tool in order to clear the DTCs.
  4. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

Go to Step 2

System OK