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 6 times.

### 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 a reappearance of the malfunction. If an intermittent malfunction exists, refer to Testing for Intermittent Conditions and Poor Connections .

### 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. Check if any of the other instrument cluster indicators or gages function.
2. Ignition OFF, disconnect the sensing and diagnostic module (SDM) connector
3. Ignition ON, with the engine OFF, check to see that air bag indicator turns ON.

⇒ | If air bag indicator turns ON, replace the SDM.

⇒ | If air bag indicator does not turn ON, test air bag indicator control circuit for open or high resistance.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

Control Module References for SDM replacement, setup, and programming