B0022

DTC B0022, B0024, B0026, B0042, B0043, or B0044

Circuit Description

The following diagnostics are designed to diagnose circuit failures for both single stage and dual stage air bag systems. The light duty G/H models are equipped with dual stage air bags and the heavy duty G/H models are equipped with single stage air bags. 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. There are shorting bars used within 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 diagnostic trouble code (DTC) will be stored in memory.

DTC Descriptors

This diagnostic procedure supports the following DTCs:

* DTC B0022 Driver Frontal Deployment Loop Resistance Low
* DTC B0024 Driver Frontal Deployment Loop Voltage Out of Range
* DTC B0026 Driver Frontal Deployment Loop Open
* DTC B0042 LF/Driver Frontal Deployment (Stage 2) Resistance Low
* DTC B0043 LF/Driver Frontal Deployment (Stage 2) Voltage Out of Range
* DTC B0044 LF/Driver Frontal Deployment (Stage 2) Open

Conditions for Running the DTC

Ignition 1 voltage is within the normal operating voltage range.

Conditions for Setting the DTC

* DTC B0022 - stage 1 or B0042 - stage 2 will set when the steering wheel module deployment loop resistance is less than 1.3 ohms for 500 milliseconds.
* DTC B0024 - stage 1 or B0043 - stage 2 will set when one of the following conditions occur:

- 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 - stage 1 or B0044 - stage 2 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 low control circuits
* An open or a high resistance in the steering wheel module high or low control circuits
* A malfunctioning shorting bar on the steering wheel module coil connector

Refer to Testing for Intermittent Conditions and Poor Connections in Diagnostic Aids. Component Tests and General Diagnostics

Test Description

Step 1 - Step 6:

Step 7 - Step 11:

The numbers below refer to the step numbers on the diagnostic table.
2. This step inspects the steering wheel module coil in-line connector.
5. This step tests for a malfunctioning steering wheel module or steering wheel module coil.
7. This step tests for current DTCs. If DTC B0022 or B0042 is present, test for a short between the steering wheel module high and steering wheel module low control circuits for stage 1 or stage 2. If DTC B0024 or B0043 is present, test for a short to ground or voltage in the steering wheel module high and steering wheel module low control circuits for stage 1 or stage 2. If DTC B0026 or B0044 is present, test for an open or high resistance in the steering wheel module high and steering wheel module low control circuits for stage 1 or stage 2.