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 RUN, the IGN 1 Fuse applies battery voltage to the AIR BAG warning lamp that is connected to INFLATABLE RESTRAINT INDICATOR, terminal 6. The SIR Fuse applies battery voltage to the IGNITION input, terminal 5. 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 J 39200 Digital Multimeter with the correct terminal adapter from J 35616 Connector Test Adapter Kit. When a check for proper connection is requested, refer to Intermittents and Poor Connections . When a wire, connector or terminal repair is requested, use J-38125 Terminal Repair Kit and refer to Wiring Repair .

### 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 bulb.

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 IGN 1 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 and inflatable restraint IP module yellow 2-way connector located near the base of the steering column and behind the RH insulator panel.
3. Disconnect the inflatable restraint Sensing and Diagnostic Module (SDM). Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement .
4. Insert the J 42113 SIR Shorting Bar Tool into the SDM harness connector above terminals 6 and 7.
5. Turn the ignition switch to the RUN position.
6. Measure the voltage on the SDM harness connector from terminal 6 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 Panel Cluster Replacement in Instrument Panel, Gages and Console.
3. Turn the ignition switch to the RUN position.
4. Measure the voltage on the SDM harness connector from terminal 6 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 Panel Cluster Replacement in Instrument Panel, Gages and Console.
3. Check for proper connection to the instrument cluster at terminal F.

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 F to the SDM harness connector terminal 6. Is the resistence 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 Panel 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 IGN 1 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 IGN 1 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 and inflatable restraint IP module yellow 2-way connector located near the base of the steering column and behind the RH insulator panel.
2. Disconnect the instrument cluster. Refer to Instrument Panel Cluster Replacement in Instrument Panel, Gages and Console.
3. Replace the IGN 1 Fuse.
4. Turn the ignition switch to the RUN position for 10 seconds.
5. Turn the ignition switch to the OFF position.
6. Remove the IGN 1 Fuse.
7. 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 39.
2. Replace the IGN 1 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. Installthe IGN 1 Fuse.

Are the repairs complete?

--

Go to Step 22

--

16 | Install the IGN 1 Fuse. Are the repairs complete? | -- | Go to Step 22 | --
17 |

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

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 I to each terminal of the IGN 1 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 39.
2. Install the IGN 1 Fuse.

Are the repairs complete?

--

Go to Step 22

--

21 |

1. Repair an open condition in the power feed to the IGN 1 Fuse.
2. Install the IGN 1 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 | --