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

### Circuit Description

When you first turn the ignition switch to the ON position, the inflatable restraint Sensing and Diagnostic Module (SDM) performs tests to diagnose critical malfunctions within itself. The SDM monitors the voltages at DRIVER SIDE LOW terminal 9 and PASSENGER SIDE LOW terminal 8 to calculate the combined resistance of the steering wheel module, the steering wheel module coil and their associated wiring.

### Conditions for Setting the DTC

The SDM detects an open circuit or high resistance in the driver deployment loop.

### Action Taken When the DTC Sets

• | The SDM sets a Diagnostic Trouble Code.

• | The SDM turns ON the AIR BAG warning lamp.

### Conditions for Clearing the DTC

All DTCs are cleared with each ignition cycle.

### Test Description

1. This test checks for an open in the driver side low and high circuits.

2. This test determines if the malfunction is caused by the SDM.

3. This test determines if the malfunction is caused by the inflatable restraint steering wheel module.

4. This test checks for an open in the inflatable restraint steering wheel module coil.

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. Turn the ignition switch to the OFF position.
2. Disconnect the inflatable restraint Sensing and Diagnostic Module (SDM).
3. Disconnect and remove the inflatable restraint steering wheel module from the steering column.
4. Zero the J 39200 .
5. Measure the resistance at the inflatable restraint steering wheel module coil connector C4 between terminal 1 and 2.

Is the resistance measured less than the specified value?

1ohms

Go to Step 3

Go to Step 5

3 |

1. Connect the SDM.
2. Connect a jumper wire between terminals 1 and 2 of the steering wheel module coil connector C4.
3. Turn the ignition switch to the ACC or ON position and wait 20 seconds.
4. Clear SIR DTCs.
5. Read SIR DTCs

Is DTC 14 present?

--

Go to Step 6

Go to Step 4

4 |

1. Turn the ignition switch to the OFF position.
2. Connect the steering wheel module connector.
3. Turn the ignition switch to ACC or ON and wait 20 seconds.
4. Clear SIR DTCs.
5. Read SIR DTCs.

Is DTC 14 present?

--

Go to Step 7

Go to Step 10

5 |

1. Disconnect the inflatable restraint steering wheel module coil connector C3 between the coil and the IP wiring harness.
2. Zero the J 39200 .
3. Measure the resistance between the steering wheel module coil connector C4 terminals 1 and 2.

Is the resistance measured less than the specified value?

1 ohms

Go to Step 9

Go to Step 8

6 | Replace the inflatable restraint Sensing and Diagnostic Module (SDM). Refer to Inflatable Restraint Sensing and Diagnostic Module Replacement . Are all the repairs complete? | -- | Go to Step 11 | --
7 | Replace the inflatable restraint steering wheel module. Refer to Inflatable Restraint Steering Wheel Module Replacement . Are all the repairs complete? | -- | Go to Step 11 | --
8 | Replace the inflatable restraint steering wheel module coil. Refer to Inflatable Restraint Steering Wheel Module Coil Replacement . Are all the repairs complete? | -- | Go to Step 11 | --
9 | Repair the IP wiring harness between the steering wheel module coil and the SDM. Refer to Wiring Repair . Are all the repairs complete? | -- | Go to Step 11 | --
10 | An intermittent exists in the driver deployment loop. Refer to diagnostic aids. Are all the repairs complete? | -- | Go to Step 11 | --
11 | Reconnect all SIR components. Make sure all components are properly mounted. Have all the SIR components been reconnected and properly mounted? | -- | Go to SIR Diagnostic System Check | --