For 1990-2009 cars
SIR Components
SIR Schematics
SIR Caution
Handling ESD Sensitive Parts Notice
SIR Caution
SIR Caution

### Circuit Description

When the ignition switch is first turned to RUN, the IPC/BFC Fuse applies battery voltage to the AIR BAG warning lamp that is connected to INFLATABLE RESTRAINT INDICATOR, terminal 7. The AIR BAG Fuse applies battery voltage to the IGNITION 1 input, terminal 10. The inflatable restraint Sensing and Diagnostic Module (SDM) responds by flashing the AIR BAG warning lamp seven times.

When measurements are requested in this table, use the J 39200 DMM with the correct terminal adapter from the J 35616 Connector Test Adapter Kit. When an inspection for proper connection is requested, refer to Testing for Electrical Intermittents in Wiring Systems. When a wire, connector or terminal repair is requested, use the J-38125 Terminal Repair Kit and refer to Wiring Repairs in Wiring Systems.

### Test Description

The numbers below refer to the step numbers on the diagnostic table:

1. This test determines whether the malfunction is in the inflatable restraint sensing and diagnostic module (SDM) circuitry or in the instrument cluster power feed circuitry.

2. This test determines whether voltage is present in the warning lamp circuit.

3. This test isolates CKT 358 and checks for a short in CKT 358 to B+.

4. This test determines if the malfunction is in the instrument cluster connector.

5. This test determines if the open is due to a bad LED.

6. This test checks whether power is available to the instrument cluster power feed circuit.

7. This test checks for a short from the instrument cluster power feed circuit to ground.

8. This test determines whether the short to ground is due to a short in the wiring or internal to the instrument cluster.

9. This test determines if the malfunction is in the instrument cluster connector.

10. This test determines whether the malfunction is due to an open power feed circuit from the IPC/BFC Fuse.

#### Air Bag Warning Lamp Does Not Come On

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Was the SIR Diagnostic System Check performed? | -- | Go to Step 2 | Go to SIR Diagnostic System Check
2 |

1. Set the parking brake.
2. Turn the ignition switch to the RUN position.

Does the BRAKE indicator light?

--

Go to Step 3

Go to Step 11

3 |

1. Turn the ignition switch to the OFF position.
2. Disconnect the inflatable restraint steering wheel module yellow 2-way connector located inside the LH I/P wiring harness junction block.
3. Disconnect the inflatable restraint I/P module yellow 2-way connector located inside the RH I/P wiring harness junction block.
4. Disconnect the inflatable restraint Sensing and Diagnostic Module (SDM). Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement .
5. Install J 38715-96 SIR Shorting Bar Tool to the SDM harness connector.
6. Install the CPA.
7. Turn the ignition switch to the RUN position.
8. Measure the voltage on the SDM harness connector from terminal 7 to ground.

Is the voltage more than the specified value?

10.0 V

Go to Step 4

Go to Step 6

4 |

1. Turn the ignition switch to the OFF position.
2. Disconnect the instrument cluster. Refer to Instrument Cluster Replacement in Instrument Panel, Gauges and Console.
3. Turn the ignition switch to the RUN position.
4. Measure the voltage on the SDM harness connector from terminal 7 to ground.

Is the voltage less than the specified value?

1.0 V

Go to Integrity Check

Go to Step 5

5 |

1. Turn the ignition switch to the OFF position.
2. Repair a short-to-B+ condition in CKT 358.
3. Reconnect the instrument cluster.

Are the repairs complete?

--

Go to Step 22

--

6 |

1. Turn the ignition switch to the OFF position.
2. Remove the instrument cluster. Refer to Instrument Cluster Replacement in Instrument Panel, Gauges and Console.
3. Check for proper connection to the instrument cluster at terminal B12.

Is the connector damaged or corroded?

--

Go to Step 7

Go to Step 8

7 | Repair the instrument cluster harness connector. Refer to Connector Repairs in Wiring Systems. Are the repairs complete? | -- | Go to Step 22 | --
8 | Measure the resistance from the instrument cluster harness connector terminal C15 to the SDM harness connector terminal 7. Is the resistance reading within the specified values? | 0-5 ohms | Go to Step 10 | Go to Step 9
9 |

1. Repair an open condition in CKT 358.
2. Install the instrument cluster.

Are the repairs complete?

--

Go to Step 22

--

10 | Service the instrument cluster. Refer to Instrument Cluster Replacement in Instrument Panel, Gauges and Console. Are the repairs complete? | -- | Go to Step 22 | --
11 |

1. Turn the ignition switch to the OFF position.
2. Remove the IPC/BFC Fuse.
3. Inspect the fuse.

Is the fuse good?

--

Go to Step 17

Go to Step 12

12 |

1. Replace the fuse.
2. Turn the ignition switch to the RUN position for 10 seconds.
3. Turn the ignition switch to the OFF position.
4. Remove the IPC/BFC Fuse.
5. Inspect the fuse.

Is the fuse good?

--

Go to Step 16

Go to Step 13

13 |

1. Disconnect the inflatable restraint steering wheel module yellow 2-way connector located inside the LH I/P wiring harness junction block.
2. Disconnect the inflatable restraint I/P module yellow 2-way connector located inside the RH I/P wiring harness junction block.
3. Disconnect the instrument cluster. Refer to Instrument Cluster Replacement in Instrument Panel, Gauges and Console.
4. Replace the IPC/BFC Fuse.
5. Turn the ignition switch to the RUN position for 10 seconds.
6. Turn the ignition switch to the OFF position.
7. Remove the IPC/BFC Fuse.
8. Inspect the fuse.

Is the fuse good?

--

Go to Step 15

Go to Step 14

14 |

1. Repair a short-to-ground condition in CKT 1600.
2. Replace the IPC/BFC Fuse.

Are the repairs complete?

--

Go to Step 22

--

15 |

1. Service the instrument cluster. Refer to Instrument Cluster Replacement in Instrument Panel, Gauges and Console.
2. Install the IPC/BFC Fuse.

Are the repairs complete?

--

Go to Step 22

--

16 | Install the IPC/BFC Fuse. Are the repairs complete? | -- | Go to Step 22 | --
17 |

1. Remove the instrument cluster. Refer to Instrument Cluster Replacement in Instrument Panel, Gauges and Console.
2. Check for proper connection to the instrument cluster at terminal B9.

Is the connector damaged or corroded?

--

Go to Step 18

Go to Step 19

18 | Repair the instrument cluster harness connector. Refer to Connector Repairs in Wiring Systems. Are the repairs complete? | -- | Go to Step 22 | --
19 | Measure the resistance between the instrument cluster harness connector terminal B12 to each terminal of the IPC/BFC Fuse fuseholder. Is either reading within the specified values? | 0-5 ohms | Go to Step 21 | Go to Step 20
20 |

1. Repair an open condition in CKT 1600.
2. Install the IPC/BFC Fuse.

Are the repairs complete?

--

Go to Step 22

--

21 |

1. Repair an open condition in the power feed to the IPC/BFC Fuse.
2. Install the IPC/BFC Fuse.

Are the repairs complete?

--

Go to Step 22

--

22 | Reconnect all the SIR system components, make sure all the components are properly mounted. Have all the SIR components been reconnected and properly mounted? | -- | Go to SIR Diagnostic System Check | --