For 1990-2009 cars

### Circuit Description

The ignition switch supplies ignition 1 voltage to the inflatable restraint sensing and diagnostic module (SDM). The ignition switch also supplies battery voltage to the AIR BAG indicator using the F3 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 7 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 .

### Test Description

The number below refers to the step number on the diagnostic table.

1. This step tests for proper operation of the Air Bag Indicator Control circuitry. With the SDM connector disconnected, the shorting bar connects the Air Bag Indicator Control circuit to ground and should illuminate the indicator.

Step | Action | Yes | No
--- | --- | --- | ---
Schematic Reference: SIR Schematics Connector End View Reference: SIR Connector End Views
1 | Did you perform a Diagnostic System Check - Vehicle? | Go to Step 2 | Go to Diagnostic System Check - Vehicle
2 | Do any of the other instrument cluster indicators or gages function? | Go to Step 3 | Go to Symptoms - Displays and Gages
3 |

1. Turn OFF the ignition.
2. Disconnect the sensing and diagnostic module (SDM) connector.
3. Turn ON the ignition, with the engine OFF.

Does the AIR BAG indicator come ON?

Go to Step 5

Go to Step 4

4 |

1. Turn OFF the ignition.
2. Inspect the SDM connector for the following conditions:

• | Corrosion

• | Damaged terminals

• | Poor connections/terminal tension

Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 7

Go to Step 6

5 | Replace the SDM. Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement . Did you complete the replacement? | Go to Step 7 | --
6 | Repair the open or high resistance in the Air Bag Indicator Control circuit. Refer to Wiring Repairs . Did you find and correct the condition? | Go to Step 7 | --
7 | Operate the system in order to verify the repair. Did you correct the condition? | System OK | Go to Step 2