For 1990-2009 cars

Important: Complete the following steps before using the symptom tables:

1. Perform Diagnostic System Check - SIR before using the symptom tables in order to verify that all of the following are true:

1.1. | There are no DTCs set.

1.2. | The inflatable restraint sensing and diagnostic and seat belt pretensioner module (SDM) can communicate via the serial data link.

2. Review the system operation in order to familiarize yourself with the system functions. Refer to SIR System Operation .

### Visual/Physical Inspection

• | Inspect for aftermarket devices which could affect the operation of the SIR system. Refer to Checking Aftermarket Accessories in Wiring Systems.

• | Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.

### Intermittent

Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

### Symptom List

Refer to AIR BAG Warning Lamp Comes On Steady or AIR BAG Warning Lamp Does Not Come On in order to diagnose the symptom.