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 provide an overview of each diagnostic category |
Diagnostic Fault Information
Circuit | Short to Ground | Low Resistance | High Resistance | Open | Short to Voltage |
|---|---|---|---|---|---|
Steering Wheel Module - Low Control | B0024 | B0022 | B0026 | B0026 | B0024 |
Steering Wheel Module - High Control | B0024 | B0022 | B0026 | B0026 | B0024 |
DTC Descriptors
DTC B0022 : Driver Frontal Deployment Loop Resistance LowDTC B0024: Driver Frontal Deployment Loop Voltage Out of Range
DTC B0026 : Driver Frontal Deployment Loop Open
Circuit Description
The inflatable restraint steering wheel module deployment loop consists of a steering wheel module, steering wheel module coil, steering wheel module high control, and steering wheel module low control circuits. Shorting bars are used on the steering wheel module connector as well as the steering wheel module coil connector which will short together the steering wheel module high and steering wheel module low control circuits when the connector is disconnected. This will help to prevent unwanted deployment of the inflator module during servicing. When the ignition is turned ON, the inflatable restraint sensing and diagnostic module (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 1 voltage is within the normal operating voltage range.
Conditions for Setting the DTC
| • | DTC B0022 will set when the steering wheel module deployment loop resistance is less than 1.3 ohms for 500 milliseconds. |
| • | DTC B0024 will set when one of the following conditions occurs: |
| - | The SDM detects the voltage at steering wheel module high control is shorted to ground or voltage for 500 milliseconds. |
| - | The SDM detects the voltage at steering wheel module high control is less than 2.4 volts and steering wheel module deployment loop resistance is less than 6 ohms for 500 milliseconds. |
| • | DTC B0026 will set when one of the following conditions occurs: |
| - | The SDM detects the steering wheel module deployment loop resistance is greater than 4.8 ohms for 500 milliseconds. |
| - | The SDM detects the voltage at steering wheel module high control is less than 2.4 volts and steering wheel module deployment loop resistance is 6 ohms or greater for 500 milliseconds. |
Action Taken When the DTC Sets
The SDM commands the AIR BAG indicator ON via class 2 serial data.
Conditions for Clearing the DTC
| • | The condition responsible for setting the DTC no longer exists. |
| • | You issue a scan tool CLEAR DTCs command. |
| • | A history DTC will clear once 255 malfunction-free ignition cycles have occurred. |
Diagnostic Aids
The following can cause an intermittent condition:
| • | A short between the steering wheel module high and steering wheel module low control circuits |
| • | A malfunctioning shorting bar on the steering wheel module connector |
| • | A malfunctioning shorting bar on the steering wheel module coil connector |
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
SIR System Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Special Tools
J 38715-A Driver and Passenger SIR Load Tool
Circuit/System Testing
Note: Refer to SIR Warning prior to servicing the SIR system.
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 inflatable restraint module |
| • | The SDM module |
| • | The inflatable restraint module wiring harness connector |
| • | The SDM wiring harness connector |
- Ignition OFF, disconnect the harness connector at the steering wheel module.
- Ignition ON, test for less than 1 volt between the high control circuit terminal A and ground.
- Test for less than 1 volt between the low control circuit terminal B and ground.
- Ignition OFF, test for infinite resistance between the high control circuit terminal A and ground.
- Test for infinite resistance between the low control circuit terminal B and ground.
- With the applicable adaptor, connect special tool J 38715-A in place of the steering wheel module.
- Ignition ON, verify the DTC is set as current.
- Ignition OFF, disconnect special tool J 38715-A and the applicable adaptor.
- Disconnect the harness connector at the SDM.
- Test for less then 1 ohm between the high control circuit terminals A and A6.
- 11. Test for less then 1 ohm of resistance between the low control circuit terminals B and A7.
- If all circuits test normal, replace the SDM.
| ⇒ | If greater than the specified range, test the high control circuit for a short to voltage. If the circuit tests normal, replace the SDM. |
| ⇒ | If greater than the specified range, test the low control circuit for a short to voltage. If the circuit tests normal, replace the SDM. |
| ⇒ | If not the specified value, test the high control circuit for a short to ground. If the circuit tests normal, replace the SDM. |
| ⇒ | If not the specified value, test the low control circuit for a short to ground. If the circuit tests normal, replace the SDM. |
| ⇒ | If the DTC is not set or is set as history, replace the steering wheel module. |
| ⇒ | If not within the specified range, test the circuit for an open/high resistance. |
| ⇒ | If not within the specified range, test the circuit for an open/high resistance. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
| • | Control Module References for SDM replacement, setup, and programming |
