B0022

CIRCUIT DESCRIPTION

SIR Schematics:

The steering wheel module deployment loop consists of an inflatable restraint steering wheel module, an inflatable restraint steering wheel module coil, the steering wheel module - high control circuit, and the steering wheel module - low control circuit. A shorting bar is used in the inflatable restraint steering wheel module and the inflatable restraint steering wheel module coil connectors which will short together the steering wheel module - high control 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. During a frontal crash of sufficient force the Sensing And Diagnostic Module (SDM) will allow current to flow through the deployment loop in order to deploy the inflatable restraint 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.

CONDITIONS FOR RUNNING THE DTC
Ignition 1 Voltage is within the normal operating voltage range.

CONDITIONS FOR SETTING THE DTC
The steering wheel module deployment loop resistance is less than 1.3 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
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.

The following are possible causes of the malfunction:
^ A short between the steering wheel module - high control and the steering wheel module - low control circuits.
^ A malfunctioning inflatable restraint steering wheel module.
^ A malfunctioning inflatable restraint steering wheel module coil.
^ An internal SDM malfunction.

If an intermittent malfunction exists, refer to Testing for Intermittent and Poor Connections in Diagrams.

TEST DESCRIPTION

Steps 1-3:

Steps 4-12:

The number(s) below refer to the step number(s) on the diagnostic table.
4. Tests to see if the malfunction is intermittent
5. Tests to see if the malfunction is caused by either the inflatable restraint steering wheel module or steering wheel module coil
6. Determines whether the malfunction is caused by the steering wheel module or the steering wheel module coil
10. Tests for a short between the steering wheel module - high control and steering wheel module - low control circuits