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 LowDTC 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 diagnostic trouble code (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
Connector End View Reference
Electrical Information Reference
Special Tools Required
| • | J 38715-A SIR Driver/Passenger Load Tool |
| • | J 38715-80 Load Tool Adapter (Dual Stage) |
| • | J 38715-100 Load Tool Adapter (Single Stage) |
| • | J 38715-120 Load Tool Adapter (Dual Stage) |
| • | J 38715-30A Load Tool Adapter (Single Stage) |
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 air bag module |
| • | The SDM module |
| • | The steering wheel module coil |
| • | The air bag wiring harness connector |
| • | The SDM wiring harness connector |
- Verify that the steering wheel module connector and the CPA are engaged.
- Ignition OFF, disconnect the steering wheel module.
- Use J 38715-120 or J 38715-30A adapter to connect the J 38715-A to the harness side of the steering wheel module connector.
- Ignition ON, with a scan tool , verify that DTC B0022, B0024, B0026, B0042, B0043 or B0044 is set as current.
- Ignition OFF, disconnect special tool J 38715-A .
- Ignition OFF, disconnect the steering wheel module coil in-line connector.
- Use J 38715-80 or J 38715-100 adapter to connect the J 38715-A to the harness side of the steering wheel module coil in-line wiring harness connector. Use the BASE of COLUMN and PASSENGER INFLATOR connectors located on the load tool.
- Ignition ON, with the scan tool, verify that DTC B0022, B0024, B0026, B0042, B0043 or B0044 is set as current.
- Test the high and low circuits between the SDM and steering wheel module coil for a short to voltage, short to ground, or open/high resistance.
Important: The connector and the connector position assurance (CPA) may seat independent of each other. Both the connector and the 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. |
| ⇒ | If DTC is not set or is set as history, replace the steering wheel module. |
Important: Refer to Inflatable Restraint Steering Wheel Module Coil Replacement for location of connector.
| ⇒ | If DTC is not set or is set as history, replace the steering wheel module coil. |
Important: Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement for connector location.
| ⇒ | If all test normal, replace the SDM. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for SDM replacement, setup, and programming |
