For 1990-2009 cars

### 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 (Single Stage or Stage 1) Resistance Low
DTC B0024 : Driver Frontal Deployment Loop (Single Stage or Stage 1) Voltage Out of Range
DTC B0026 : Driver Frontal Deployment Loop (Single Stage or 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

The driver deployment loop consists of a dual-stage inflatable restraint steering wheel module and a inflatable restraint steering wheel module coil. The steering wheel module high circuits and the steering wheel low circuits exist for both stages 1 and 2.

There are 2 shorting bars used within the steering wheel module coil connector. These shorting bars short together both stages of the steering wheel module high circuit, and the steering wheel module low circuit when the connector is disconnected. This helps 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. This flow of current will 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 DTC will be stored in memory.

### 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 driver module deployment loop resistance is less than 1.3 ohms for 500 milliseconds.

#### B0024 Stage 1 or B0043 Stage 2

• | The driver module stage 1 or stage 2 high and/or low circuits are shorted to voltage or shorted to ground for 500 milliseconds.

• | The driver module stage 1 or stage 2 high circuit is less than 2.4 volts and driver module stage 1 or stage 2 deployment loop resistance is less than 6 ohms for 500 milliseconds.

#### B0026 Stage 1 or B0044 Stage 2

• | The driver module stage 1 or stage 2 high circuit is less than 2.4 volts and the driver module stage 1 or stage 2 deployment loop is greater than 6 ohms for 500 milliseconds.

• | The driver module stage 1 or stage 2 deployment loop resistance is greater than 4.8 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 SIR system is disabled and no deployments are allowed.

### 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 SIR Driver/Passenger Load Tool

• | J 38715-80 Load Tool Adapter

• | J 38715-120 Load Tool Adapter

### Circuit/System Testing

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

• | Inflatable restraint module

• | SDM module

• | Inflatable restraint module 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.

⇒ | If the above condition is found, make the appropriate repair.

2. Ignition OFF, disconnect the appropriate 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 the appropriate DTC is set as current.

⇒ | If the DTC is not set or is set as history, cycle the ignition OFF, disconnect the adapter and J 38715-A , 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.

5. Ignition OFF, disconnect special tool J 38715-A .
6. Disconnect the X1 and X2 harness connectors at the steering wheel module coil.
7. With the appropriate load tool adaptor, connect special tool J 38715-A in place of the steering wheel module.
8. Ignition ON, verify the DTC is set as current.

⇒ | If the 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 the adaptor.
10. Disconnect the harness connector at the SDM.
11. Ignition ON, test for less than 1 volt between the appropriate high circuit listed below and ground:

• | Steering wheel module coil connector Stage 1 terminal A X1

• | Steering wheel module coil connector Stage 2 terminal A X2

⇒ | If not within the specified range, test the circuit for a short to voltage.

12. Test for less than 1 volt between the appropriate low circuit listed below and ground:

• | Steering wheel module coil connector Stage 1 terminal B X1

• | Steering wheel module coil connector Stage 2 terminal B X2

⇒ | If not within the specified range, test the circuit for a short to voltage.

13. Ignition OFF, test for infinite resistance between the appropriate high circuit listed below and ground:

• | Steering wheel module coil connector Stage 1 terminal A X1

• | Steering wheel module coil connector Stage 2 terminal A X2

⇒ | If not the specified value, test the circuit for a short to ground.

14. Test for infinite resistance between the appropriate low circuit listed below and ground:

• | Steering wheel module coil connector Stage 1 terminal B X1

• | Steering wheel module coil connector Stage 2 terminal B X2

⇒ | If not the specified value, test the circuit for a short to ground.

15. Test for less then 1 ohm between the high control circuit terminals listed below:

• | Steering wheel module coil connector Stage 1 terminal A X1 and SDM terminal 13

• | Steering wheel module coil connector Stage 2 terminal A X2 and SDM terminal 34

⇒ | If greater than the specified range, test the circuit for an open/high resistance.

16. Test for less then 1 ohm between the low control circuit terminals listed below:

• | Steering wheel module coil connector Stage 1 terminal B X1 and SDM terminal 12

• | Steering wheel module coil connector Stage 2 terminal B X2 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.

• | Inflatable Restraint Steering Wheel Module Coil Replacement

• | Inflatable Restraint Steering Wheel Module Replacement

• | Control Module References for SDM replacement, setup, and programming