GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptors

DTC B0012 01: Driver Frontal Deployment Loop Stage 1 Short to Battery

DTC B0012 02: Driver Frontal Deployment Loop Stage 1 Short to Ground

DTC B0012 04: Driver Frontal Deployment Loop Stage 1 Open Circuit

DTC B0012 0D: Driver Frontal Deployment Loop Stage 1 Resistance Above Threshold

DTC B0012 0E: Driver Frontal Deployment Loop Stage 1 Resistance Below Threshold

DTC B0013 01: Driver Frontal Deployment Loop Stage 2 Short to Battery

DTC B0013 02: Driver Frontal Deployment Loop Stage 2 Short to Ground

DTC B0013 04: Driver Frontal Deployment Loop Stage 2 Open Circuit

DTC B0013 0D: Driver Frontal Deployment Loop Stage 2 Resistance Above Threshold

DTC B0013 0E: Driver Frontal Deployment Loop Stage 2 Resistance Below Threshold

Diagnostic Fault Information

Circuit

Short to Ground

Low Resistance

High Resistance

Open

Short to Voltage

Steering Wheel Module Stage 1 High Control

B0012 02

B0012 0E

B0012 0D

B0012 04

B0012 01

Steering Wheel Module Stage 1 Low Control

B0012 02

B0012 0E

B0012 0D

B0012 04

B0012 01

Steering Wheel Module Stage 2 High Control

B0013 02

B0013 0E

B0013 0D

B0013 04

B0013 01

Steering Wheel Module Stage 2 Low Control

B0013 02

B0013 0E

B0013 0D

B0013 04

B0013 01

Circuit/System Description

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.

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.

Conditions for Running the DTC

Ignition voltage is between 9-16 volts.

Conditions for Setting the DTC

B0012 01 Stage 1 or B0013 01 Stage 2

The steering wheel module high and/or low circuit is shorted to voltage for 120 milliseconds.

B0012 02 Stage 1 or B0013 02 Stage 2

The steering wheel module high and/or low circuit is shorted 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 greater 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 requests the instrument panel cluster (IPC) to illuminate the AIR BAG indicator.
    • The SDM will store a DTC, however if an event occurs the system will still attempt deployments.

Conditions for Clearing the DTC

    • The condition for setting the DTC no longer exists.
    • A history DTC will clear once 100 malfunction-free ignition cycles have occurred.

Reference Information

Schematic Reference

SIR Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

SIR System Description and Operation

Electrical Information Reference

    •  Circuit Testing
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs
    •  Connector Repairs

Scan Tool Reference

Control Module References for scan tool information

Special Tools

J 38715-A SIR Driver/Passenger Load Tool

Circuit/System Testing

    Important: Refer to SIR Service Precautions.

    When removing the connectors inspect for damage or corrosion. Damage or corrosion to the following requires repair or replacement of the affected component/connector:

       • Pretensioner
       • Air bag module
       • SDM module
       • Air bag wiring harness connector
       • SDM wiring harness connector

  1. Verify that the steering wheel inflator restraint module connector and CPA are engaged.
  2. If the above condition is not found, make the appropriate repair.
  3. Ignition OFF, disconnect the harness connector at the steering wheel inflator module.
  4. With the appropriate load tool adaptor, connect J 38715-A or SA9409Z-A in place of the steering wheel inflator module.
  5. Ignition ON, with a scan tool, verify the appropriate DTC is set as current.
  6. If the DTC is not set or is set as history, cycle ignition OFF, disconnect the load tool and adapter, reconnect the harness connector at the steering wheel inflator module, and cycle the ignition ON. If the DTC resets after reconnecting the module, replace the steering wheel inflator module.
  7. Ignition OFF, disconnect the load tool and the adaptor.
  8. Disconnect the steering wheel module coil in-line harness connector X275.
  9. With the appropriate load tool adaptor, connect special tool J 38715-A in place of the steering wheel module.
  10. Ignition ON, with a scan tool, verify DTC is set as current.
  11. If DTC is not set or is set as history, replace the steering wheel module coil.
  12. Ignition OFF, disconnect load tool and the adaptor.
  13. Disconnect the harness connector at the SDM.
  14. Ignition ON, test for less than 1 volt between the appropriate high control circuit listed below and ground:
  15. • Stage 1 steering wheel module coil connector terminal 2 X275
    • Stage 2 steering wheel module coil connector terminal 4 X275
    If not the specified range, test the high control circuit for a short to voltage.
  16. Test for less than 1 volt between the appropriate low control circuit listed below and ground:
  17. • Stage 1 steering wheel module coil connector terminal 1 X275
    • Stage 2 steering wheel module coil connector terminal 3 X275
    If not the specified range, test the low control circuit for a short to voltage.
  18. Ignition OFF, test for infinite resistance between the appropriate high control circuit listed below and ground:
  19. • Stage 1 steering wheel module coil connector terminal 2 X275
    • Stage 2 steering wheel module coil connector terminal 4 X275
    If not the specified range, test the high control circuit for a short to ground.
  20. Test for infinite resistance between the appropriate low control circuit listed below and ground:
  21. • Stage 1 steering wheel module coil connector terminal 1 X275
    • Stage 2 steering wheel module coil connector terminal 3 X275
    If not the specified range, test the low control circuit for a short to ground.
  22. Test for less then 1 ohm between the following high control circuit terminals listed below:
  23. • Stage 1 steering wheel module coil connector terminal 2 X275 and SDM terminal 9
    • Stage 2 steering wheel module coil connector terminal 4 X275 and SDM terminal 5
    If not the specified range, test the high control circuit for an open/high resistance.
  24. Test for less then 1 ohm between the following low control circuit terminals listed below:
  25. • Stage 1 steering wheel module coil connector terminal 1 X275 and SDM terminal 8
    • Stage 2 steering wheel module coil connector terminal 3 X275 and SDM terminal 4
    If not the specified range, test the low control circuit for an open/high resistance.
  26. If all circuits test normal, replace the SDM.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Inflatable Restraint Steering Wheel Module Coil Replacement
    •  Inflatable Restraint Steering Wheel Module Replacement
    •  SIR/SRS Wiring Repairs
    •  Control Module References for SDM replacement, setup, and programming