Standard Air Bags

CIRCUIT DESCRIPTION

SIR Schematics: Standard Air Bags (Power, Grounds And Side Impact Sensors):

SIR Schematics: Standard Air Bags (Inflator Modules):

The driver deployment loop consists of an inflatable restraint steering wheel module, inflatable restraint steering wheel module coil, the steering wheel module high and steering wheel module low circuits. A shorting bar is used in the inflatable restraint steering wheel module connector which will short together the steering wheel module high and steering wheel module low 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 inflatable restraint 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 in non-volatile memory.

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

CONDITIONS FOR SETTING THE DTC
Steering wheel module high is less than 2.4 volts, steering wheel module deployment loop resistance is greater or equal to 6 ohms for 500 milliseconds.

Steering wheel module deployment loop resistance is more than 4.8 ohms for 500 milliseconds.

ACTION TAKEN WHEN THE DTC SETS
The SDM commands ON the AIR BAG warning lamp 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:
^ The wire to terminal connections in the steering wheel module high and/or steering wheel module low circuit.
^ The steering wheel module wiring harness connector.
^ The steering wheel module coil wiring harness connector.
^ The SDM wiring harness connector.

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 Diagrams. Diagnostic Aids

TEST DESCRIPTION

Steps 1-2:

Steps 3-11:

The number(s) below refer to the step number(s) on the diagnostic table.
5. Tests to see if the malfunction is caused by the steering wheel module or by the steering wheel module coil.
9. Tests for a open or high resistance in the steering wheel module high and steering wheel module low circuits.