For 1990-2009 cars

### Diagnostic Instructions

• | Perform the Diagnostic System Check - Vehicle prior to using the diagnostic procedure.

• | Review Strategy Based Diagnosis for an overview of the diagnostic approach.

• | Diagnostic Procedure Instructions provides an overview of each diagnostic category.

### Circuit/System Description

The ignition switch supplies ignition 1 voltage to the inflatable restraint sensing and diagnostic module (SDM) using the F10 fuse. The ignition switch also supplies battery voltage to the AIR BAG indicator using the F1 fuse. The AIR BAG indicator is connected to the AIR BAG indicator output of the SDM. When the ignition switch is first turned to the ON position, the SDM responds by flashing the AIR BAG indicator six times.

### Diagnostic Aids

In order to disable the shorting bar between the air bag indicator control circuit and ground inside the SDM wiring harness connector, the following two conditions must be met:

• | The SDM wiring harness connector must be properly connected to the SDM.

• | The connector position assurance (CPA) must be properly installed in the SDM wiring harness connector.

### Reference Information

#### Schematic Reference

SIR Schematics

#### Connector End View Reference

Component Connector End Views

#### Electrical Information Reference

• | Circuit Testing

• | Connector Repairs

• | Testing for Intermittent Conditions and Poor Connections

• | Wiring Repairs

### Circuit/System Testing

Important: When removing connectors inspect for damage or corrosion. Damage or corrosion in the following requires repair or replacement of the affected component/connector.

• | The I/P module

• | The SDM module

• | The I/P wiring harness connector

• | The SDM wiring harness connector

1. Ignition Off, disconnect the sensing and diagnostic module (SDM) connector.
2. Inspect the SDM connector and the shorting bar for damage or corrosion.

⇒ | If above conditions are present, repair or replace connector as necessary.

3. Test the air bag indicator control circuit for a short to ground.

⇒ | If circuit tests normal, replace the SDM.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for SDM replacement, setup, and programming