GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2008 🢒 XLR 🢒 Safety and Security 🢒 Supplemental Inflatable Restraints 🢒 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 Control

B0024

B0024

B0026

B0024

B0022

Steering Wheel Module Stage 1 Low Control

B0024

B0024

B0026

B0024

B0022

Steering Wheel Module Stage 2 High Control

B0043

B0043

B0044

B0043

B0042

Steering Wheel Module Stage 2 Low Control

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 greater than 6 ohms for 500 milliseconds.
    • The steering wheel module stage 1 or stage 2 deployment loop resistance is greater 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 shorted to ground or shorted 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 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
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs
    •  SIR/SRS Wiring Repairs

Scan Tool Reference

Control Module References for scan tool information

Special Tools

J 38715-A Driver and Passenger SIR 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:

   • 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 adapter and J 38715-A , 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 special tool J 38715-A and adaptor.
  6. Disconnect the in-line harness connector at the steering wheel module coil.
  7. With the appropriate load tool adaptor, connect special tool 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 special tool J 38715-A 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 connector stage 1 terminal A1
    • Steering wheel module coil connector stage 2 terminal B1
    ⇒If greater than the specified range, test the 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 connector stage 1 terminal A2
    • Steering wheel module coil connector stage 2 terminal B2
    ⇒If greater than the specified range, test the 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 connector stage 1 terminal A1
    • Steering wheel module coil connector stage 2 terminal B1
    ⇒If less than the specified value, test the 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
    • Steering wheel module coil harness connector stage 2 terminal B2
    ⇒If less than the specified value, test the circuit for a short to ground.
  15. Test for less than 1 ohm between the appropriate high control circuit terminals listed below:
    16. • Steering wheel module coil harness connector stage 1 terminal A1 and SDM terminal 13
    • Steering wheel module coil harness connector stage 2 terminal B1 and SDM terminal 34
    ⇒If greater than the specified range, test the circuit for an open/high resistance.
  16. Test for less than 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 12
    • Steering wheel module coil harness connector stage 2 terminal B2 and SDM terminal 33
    ⇒If greater than 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.

    •  Steering Wheel Inflatable Restraint Module Replacement
    •  Inflatable Restraint Steering Wheel Module Coil Centering
    •  Control Module References for SDM replacement, setup, and programming