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

### Circuit Description

When the ignition switch is first turned to ON, the IPC/BFC Fuse applies battery voltage to the AIR BAG warning indicator 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 indicator 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 voltage.

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 ON 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 ON position.
8. Measure the voltage between the SDM harness connector terminal 7 and ground.

Is the voltage greater 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 Panel Cluster Replacement in Instrument Panel, Gages and Console.
3. Turn the ignition switch to the ON position.
4. Measure the voltage on the SDM harness connector from terminal 7 to ground.

Is the voltage within the specified range?

0-1 V

Go to Sensing and Diagnostic Module Integrity Check

Go to Step 5

5 |

1. Turn the ignition switch to the OFF position.
2. Repair the short to voltage 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, Gages and Console.
3. Check for proper connection to the instrument cluster at terminal B12 (Pontiac) or terminal B5 (Oldsmobile).

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 between the instrument cluster harness connector terminal B12 (Pontiac) or terminal B5 (Oldsmobile) and the SDM harness connector terminal 7. Is the resistance reading within the specified values? | 0-2 ohms | Go to Step 10 | Go to Step 9
9 |

1. Repair the open or high resistance 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, Gages 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 open?

--

Go to Step 12

Go to Step 17

12 |

1. Replace the fuse.
2. Turn the ignition switch to the ON 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 open?

--

Go to Step 13

Go to Step 16

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, Gages and Console.
4. Replace the IPC/BFC Fuse.
5. Turn the ignition switch to the ON 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 open?

--

Go to Step 14

Go to Step 15

14 |

1. Repair the 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 Panel Cluster Replacement in Instrument Panel, Gages 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, Gages 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 A8 (Pontiac) or terminal A2 (Oldsmobile) and terminal B9 of the IPC/BFC Fuse fuseholder. Is the resistance within the specified values? | 0-2 ohms | Go to Step 21 | Go to Step 20
20 |

1. Repair the open or high resistance in CKT 1600.
2. Install the IPC/BFC Fuse.

Are the repairs complete?

--

Go to Step 22

--

21 |

1. Repair the open or high resistance 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 | --