GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2008 🢒 Express 🢒 Safety and Security 🢒 Supplemental Inflatable Restraints 🢒 DTC B0012 or B0013

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

High Resistance

Open

Short to Voltage

Signal Performance

Steering Wheel Module Stage 1 High Control

B0012 02

B0012 0D

B0012 04

B0012 01

B0012 0E

Steering Wheel Module Stage 1 Low Control

B0012 02

B0012 0D

B0012 04

B0012 01

B0012 0E

Steering Wheel Module Stage 2 High Control

B0013 02

B0013 0D

B0013 04

B0013 01

B0013 0E

Steering Wheel Module Stage 2 Low Control

B0013 02

B0013 0D

B0013 04

B0013 01

B0013 0E

Circuit/System Description

If a malfunction is detected, a DTC will be stored in non-volatile memory. 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 each 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.

Diagnostic Aids
    • When a harness connector is disconnected, the high control and low control circuits are shorted together by the integral shorting bar. This should be taken into account when testing for faults on these circuits.
    • This DTC usually indicates a poor connection or a wiring malfunction between the SDM and the deployment loop.

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
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring 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: When removing the connectors inspect for damage, corrosion or poor connection. 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

    Important: The connector and connector position assurance (CPA) may seat independent of each other. Both the connector and CPA should seat with an audible and/or tactile click. The CPA isolates the shorting-bars within the connector allowing the deployment circuit to operate properly.

  1. Verify that the steering wheel module connector and the CPA are engaged.
    2. ⇒If the above condition is not found, make the appropriate repair.
  2. Ignition OFF, disconnect the harness connector at the steering wheel module.
  3. With the appropriate load tool adaptor, connect special tool J 38715-A in place of the steering wheel module.
  4. Ignition ON, verify DTC is set as current.
    5. ⇒If the DTC is not set or is set as history, cycle ignition OFF, disconnect the load tool and adaptor, reconnect the harness connector at the steering wheel module, and cycle the ignition ON. If the DTC resets after reconnecting the module, replace the steering wheel module.
  5. Ignition OFF, disconnect the load tool and adaptor.
  6. Disconnect the harness connector at the steering wheel module coil.
  7. With the appropriate adaptor, connect special tool J 38715-A .
  8. Ignition ON, verify the DTC is set as current.
    9. ⇒If DTC is not set or is set as history, replace the steering wheel module coil.
  9. Ignition OFF, disconnect the load tool and adaptor.
  10. Disconnect the harness connector at the SDM.
  11. Ignition ON, test for less than 1 volt between the appropriate high control circuit listed below and ground:
    12. • Steering wheel module coil harness connector - Stage 1 terminal A1 (Heavy Duty)
    • Steering wheel module coil harness connector - Stage 1 terminal A1 X1 (Light Duty)
    • Steering wheel module coil harness connector - Stage 2 terminal B1 X2
    ⇒If greater than the specified range, test the control circuit for a short to voltage.
  12. Test for less than 1 volt between the appropriate low control circuit listed below and ground:
    13. • Steering wheel module coil harness connector - Stage 1 terminal A2 (Heavy Duty)
    • Steering wheel module coil harness connector - Stage 1 terminal A2 X1 (Light Duty)
    • Steering wheel module coil harness connector - Stage 2 terminal B2 X2
    ⇒If greater than the specified range, test the control circuit for a short to voltage.
  13. Ignition OFF, test for infinite resistance between the appropriate high control circuit listed below and ground:
    14. • Steering wheel module coil harness connector - Stage 1 terminal A1 (Heavy Duty)
    • Steering wheel module coil harness connector - Stage 1 terminal A1 X1 (Light Duty)
    • Steering wheel module coil harness connector - Stage 2 terminal B1 X2
    ⇒If less than the specified value, test the control circuit for a short to ground.
  14. Test for infinite resistance between the appropriate low control circuit listed below and ground:
    15. • Steering wheel module coil harness connector - Stage 1 terminal A2 (Heavy Duty)
    • Steering wheel module coil harness connector - Stage 1 terminal A2 X1 (Light Duty)
    • Steering wheel module coil harness connector - Stage 2 terminal B2 X2
    ⇒If less than the specified value, test the control circuit for a short to ground.
  15. Test for less then 5 ohms between the appropriate high control circuit terminals listed below:
    16. • Steering wheel module coil harness connector - Stage 1 terminal A1 and SDM terminal 9 (Heavy Duty)
    • Steering wheel module coil harness connector - Stage 1 terminal A1 X1 and SDM terminal 9 (Light Duty)
    • Steering wheel module coil harness connector - Stage 2 terminal B1 X2 and SDM terminal 5
    ⇒If greater than the specified range, test the control circuit for an open/high resistance.
  16. Test for less then 1 ohm between the appropriate low control circuit terminals listed below:
    17. • Steering wheel module coil harness connector - Stage 1 terminal A2 and SDM terminal 8 (Heavy Duty)
    • Steering wheel module coil harness connector - Stage 1 terminal A2 X1 and SDM terminal 8 (Light Duty)
    • Steering wheel module coil harness connector - Stage 2 terminal B2 X2 and SDM terminal 4
    ⇒If greater that the specified range, test the control circuit for an open/high resistance.
  17. If all circuits test normal, replace the SDM.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

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