B0024

CIRCUIT DESCRIPTION
The inflatable restraint steering wheel module deployment loop consists of the inflatable restraint steering wheel module, the inflatable restraint steering wheel module coil, and the steering wheel module high and low circuits. A shorting bar used within the steering wheel module coil connector shorts together the steering wheel module high and low circuits when the connector is disconnected. This helps to prevent unwanted deployment of the inflator module during servicing. During a frontal crash of sufficient force the Inflatable Restraint Sensing And Diagnostic Module (SDM) allows current to flow through the deployment loop in order to deploy the steering wheel module. When the ignition is turned ON, 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 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 300 milliseconds.
^ DTC B0024 will set when one of the following conditions occur:
^ Steering wheel module high and/or low circuits is short to ground or short to voltage for 300 milliseconds.
^ Steering wheel module high circuit is less than 2 volts and steering wheel module deployment loop resistance is less than 6 ohms for 300 milliseconds.
^ DTC B0026 will set when one of the following conditions occurs:
- Steering wheel module high circuit is less than 2 volts and the steering wheel module deployment loop resistance is more than 4.8 ohms for 500 milliseconds.
- Steering wheel module deployment loop resistance is more than 6 ohms for 300 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 and the scan tool Clear DTCs function is used.
^ A history DTC will clear once 255 malfunction free ignition cycles have occurred.

DIAGNOSTIC AIDS
The following are possible causes of the malfunction:
^ A short between the steering wheel module high and low circuits.
^ An open or a high resistance in the steering wheel module high or low circuits.
^ A short to ground or a short to voltage in the steering wheel module high or low circuits.
^ The steering wheel module coil connector
^ The SDM connector
^ A malfunctioning steering wheel module
^ A malfunctioning steering wheel module coil
^ A malfunctioning SDM

Thoroughly inspect the wiring and the connectors. An incomplete inspection of the wiring and the connectors may result in a misdiagnosis, causing a part replacement with the reappearance of the malfunction. If an intermittent malfunction exists, refer to Testing for Intermittent and Poor Connections in Diagnostic Aids.

TEST DESCRIPTION

Steps 1-6:

Steps 7-11:

The numbers below refer to the step numbers on the diagnostic table.
5. This step tests to see if the malfunction is caused by the steering wheel module or by the steering wheel module coil.
7. This step tests to see what DTCs are present. If DTC B0022 is present, test the steering wheel module for a short between high and low circuits. If DTC B0024 is present, test the steering wheel module high and low circuits for an open and for high resistance. If DTC B0026 is present, test the steering wheel module high and low circuits for an open and for high resistance.