For 1990-2009 cars

### Circuit Description

When the ignition is turned ON, the inflatable restraint sensing and diagnostic module (SDM) flashes the AIR BAG indicator seven times. The SDM performs diagnostic tests on the SIR system and then turns the AIR BAG indicator OFF if no SIR malfunctions exists. If the ignition 1 voltage is outside of the normal operating range (9-16 volts), the SDM will turn the AIR BAG indicator ON with no DTCs present.

### Diagnostic Aids

The AIR BAG indicator will turn ON if the SDM connector is damaged or not properly connected to the SDM. The AIR BAG indicator will also turn ON if the shorting bar that is located within the SDM connector is damaged. In order to disable the shorting bar from the AIR BAG indicator control circuit and the SDM ground circuit within the SDM connector, the following conditions must be met:

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

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

### Test Description

1. Tests to see if the BRAKE indicator turns ON.

2. Tests to see if there is an open or a high resistance in the AIR BAG indicator control circuit.

3. Tests to see if there is an open or a high resistance in the AIR BAG indicator voltage feed circuit.

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
Schematic Reference: SIR Schematics
1 | Did you perform the Diagnostic System Check - SIR? | -- | Go to Step 2 | Go to Diagnostic System Check - SIR
2 |

1. Turn OFF the ignition.
2. Note the AIR BAR indicator while turning ON the ignition.

Does the AIR BAG indicator remain OFF at all times?

--

Go to Step 3

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

3 |

1. Set the parking brake.
2. Turn ON the ignition, with the engine OFF.

Does the BRAKE indicator turn ON?

--

Go to Step 4

Go to Step 6

4 |

1. Turn OFF the ignition.
2. Disconnect the SDM connector. Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement .
3. Install the J 42113 SIR Shorting Bar Lifting Tool to the SDM connector in order to lift the shorting bar between the AIR BAG indicator control circuit and the SDM ground circuit.
4. Turn ON the ignition, with the engine OFF.
5. Measure the voltage between the AIR BAG indicator control circuit and a good ground.

Does the voltage measure near the specified value?

12 V

Go to Step 9

Go to Step 5

5 |

1. Turn OFF the ignition.
2. Test the AIR BAG indicator control circuit for an open or a high resistance.

Did you find and correct the condition?

--

Go to Step 10

Go to Step 6

6 |

1. Turn OFF the ignition.
2. Disconnect the instrument panel cluster (IPC) connector. Refer to Instrument Cluster Replacement in Instrument Panel, Gauges, and Console.
3. Turn ON the ignition, with the engine OFF.
4. Measure the voltage between the AIR BAG indicator voltage feed circuit and a good ground.

Does the voltage measure near the specified value?

12 V

Go to Step 8

Go to Step 7

7 |

1. Turn OFF the ignition.
2. Test the AIR BAG indicator voltage feed circuit for an open or a high resistance.

Did you find and correct the condition?

--

Go to Step 10

--

8 | Replace the IPC. Refer to Instrument Cluster Replacement in Instrument Panel, Gauges, and Console. Did you complete the replacement? | -- | Go to Step 10 | --
9 | Replace the SDM. Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement . Did you complete the replacement? | -- | Go to Step 10 | --
10 | Operate the system in order to verify the repair. Did you correct the condition? | -- | System OK | Go to Step 3