GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2007 🢒 CTS 🢒 Driver Information and Entertainment 🢒 Cellular, Entertainment, and Navigation 🢒 DTC B0022, B0024, B0026, B0042, B0043, or B0044

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 B0022: Driver Frontal Deployment Loop (Stage 1) Resistance Low

DTC B0024: Driver Frontal Deployment Loop (Stage 1) Voltage Out of Range

DTC B0026: Driver Frontal Deployment Loop (Stage 1) Open

DTC B0042: Driver Frontal Deployment Loop (Stage 2) Resistance Low

DTC B0043: Driver Frontal Deployment Loop (Stage 2) Voltage Out of Range

DTC B0044: Driver Frontal Deployment Loop (Stage 2) Open

Diagnostic Fault Information

Circuit

Short to Ground

High Resistance

Open

Short to Voltage

Signal Performance

Steering Wheel Module Stage 1 High Circuit

B0024

B0024

B0026

B0024

B0022

Steering Wheel Module Stage 1 Low Circuit

B0024

B0024

B0026

B0024

B0022

Steering Wheel Module Stage 2 High Circuit

B0043

B0043

B0044

B0043

B0042

Steering Wheel Module Stage 2 Low Circuit

B0043

B0043

B0044

B0043

B0042

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

B0022 stage 1 or B0042 stage 2

The steering wheel module deployment loop resistance is less than 1.3 ohms for 500 milliseconds.

B0024 stage 1 or B0043 stage 2

    • The steering wheel module stage 1 or stage 2 high circuit is less than 2.4 volts and the steering wheel module stage 1 or stage 2 deployment loop is more than 6 ohms for 500 milliseconds.
    • The steering wheel module stage 1 or stage 2 deployment loop resistance is more than 4.8 ohms for 500 milliseconds.

B0026 stage 1 or B0044 stage 2

    • The steering wheel module stage 1 or stage 2 high and/or low circuits is short to ground or short to voltage for 500 milliseconds.
    • The steering wheel module stage 1 or stage 2 high circuit is less than 2.4 volts and steering wheel module stage 1 or stage 2 deployment loop resistance is less than 6 ohms for 500 milliseconds.

Action Taken When the DTC Sets
    • The SDM commands the AIR BAG indicator ON via serial data communications.
    • The SIR System is disabled and no deployments are allowed.

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 100 malfunction-free ignition cycles have occurred.

Diagnostic Aids

Each air bag module requires a specific adapter to connect the load tool to the SIR system. For specific tool information refer to Special Tools .

Reference Information

Schematic Reference

SIR Schematics

Connector End View Reference

SIR 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

    •  Scan Tool Data List
    •  Scan Tool Data Definitions

Special Tools Required

J 38715-A Driver and Passenger SIR Load Tool

Circuit/System Testing

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

   • The pretensioner
   • The air bag module
   • The SDM module
   • The air bag wiring harness connector
   • The SDM wiring harness connector

  1. Verify that the steering wheel module connector and the connector position assurance (CPA) are engaged.

    2. Important: The connector and 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.

    ⇒If the above condition is found, make the appropriate repair.
  2. Ignition OFF, disconnect the steering wheel module.
  3. With the applicable adaptor, connect J 38715-A .
  4. Ignition ON, with a scan tool, verify DTC is set as current.
    5. ⇒If DTC is not set or is set as history, replace the steering wheel module.
  5. Ignition OFF, disconnect J 38715-A .
  6. Disconnect the steering wheel module coil in-line connector.
  7. With the applicable adaptor, connect J 38715-A .
  8. Ignition ON, with a scan tool, verify 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 J 38715-A and the applicable adaptor.
  10. Ignition ON, test for less than 1 volt between the applicable HI circuit and ground.
    11. ⇒If not the specified range, test the circuit for a short to voltage.
  11. Test for less than 1 volt between the applicable LOW circuit and ground.
    12. ⇒If not the specified range, test the circuit for a short to voltage.
  12. Ignition OFF, test for infinite resistance between the applicable HI circuit and ground.
    13. ⇒If not the specified range, test the circuit for a short to ground.
  13. Test for infinite resistance between the applicable LOW circuit and ground.
    14. ⇒If not the specified range, test the circuit for a short to ground.
  14. Disconnect the harness connector at the SDM.
  15. Test for less then 1 ohm of resistance between the SDM connector and the air bag module connector HI circuit.
    16. ⇒If not the specified range, test the circuit for an open/high resistance.
  16. Test for less then 1 ohm of resistance between the SDM connector and the air bag module connector LOW circuit.
    17. ⇒If not the specified range, test the 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.

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