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 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

The driver deployment loop consists of the following components:

• | A dual-stage inflatable restraint steering wheel module

• | The inflatable restraint steering wheel module coil

• | The steering wheel module high circuits for both stages 1 and 2

• | The steering wheel module low circuits 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 is short to ground or short to voltage 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 more than 6 ohms for 500 milliseconds.

• | The driver module stage 1 or stage 2 deployment loop resistance is more than 4.8 ohms for 500 milliseconds.

### Action Taken When the DTC Sets

• | The SDM commands the AIR BAG indicator ON via class 2 serial data.

• | 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 DTC function is used.

• | A history DTC will clear once 255 malfunction-free ignition cycles have occurred.

### Diagnostic Aids

If there is more than one DTC set, diagnose the open DTC first. The following conditions are possible causes of the malfunction:

• | A short between the steering wheel module stage 1 or stage 2, high and low circuits

• | An open or a high resistance in the steering wheel module stage 1 or stage 2, high or low circuits

• | A short-to-ground, or a short-to-voltage in the steering wheel module stage 1 or stage 2, high circuits or low circuits

• | A malfunctioning steering wheel module coil connector

• | A malfunctioning SDM connector

• | A malfunctioning steering wheel module

• | A malfunctioning steering wheel module coil

• | A malfunctioning SDM

### Reference Information

#### Schematic Reference

SIR Schematics

#### Connector End View Reference

SIR Connector End Views

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

• | SIR/SRS Wiring Repairs

#### Special Tools Required

• | J 38715-A SIR Driver/Passenger Load Tool

• | J 38715-80 Load Tool Adapter

• | J 38715-120 Load Tool Adapter

### Circuit/System Testing

1. With the ignition OFF, disconnect the steering wheel module coil inline connector located at the base of column. Note: Refer to Steering Wheel Module Coil Replacement for location of connector.
2. Inspect the component and wiring harness sides of the inline connector for damage or corrosion.

⇒ | If the inline connector for the steering wheel module coil is damaged, the steering wheel module coil must be replaced.

⇒ | If the steering wheel module coil wiring harness side connector is damaged, replace the harness side of the connector.

3. Use J 38715-80 adapter to connect the J 38715-A to the harness side of the steering wheel module coil inline wiring harness connector. Use the BASE of COLUMN and PASSENGER INFLATOR connectors located on the load tool.
4. With the ignition ON, use a scan tool to observe the SIR DTC display. Verify DTCs B0022, B0024, B0026, B0042, B0043, or B0044 are set as current or in history.
5. With the ignition OFF, disconnect and remove the J 38715-A and adapter.
6. If DTC B0022, B0024, B0026, B0042, B0043, or B0044 is history, reconnect the steering wheel module coil wiring harness. Use J 38715-120 adapter to connect the J 38715-A to the harness side of the steering wheel module connector. If DTC B0022, B0024, B0026, B0042, B0043, or B0044 is set as current, replace the steering wheel module coil. If DTC B0022, B0024, B0026, B0042, B0043, or B0044 are set in history, replace the steering wheel module.
7. If DTC B0022, B0024, B0026, B0042, B0043, or B0044 is current, a problem exists with the SDM and or the wiring harness. Remove the SDM connector. Inspect the SDM connector for damage or corrosion that may cause a malfunction in the steering wheel module coil stage 1 or stage 2 high and/or low circuits.

⇒ | If damage or corrosion is found make the appropriate repair.

8. Test the high and low circuits between the SDM and steering wheel module coil for a short to voltage, short to ground, or open/low resistance.

⇒ | If circuits test good, then 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