For 1990-2009 cars

### Circuit Description

When the ignition switch is first turned ON, battery voltage is applied to the AIR BAG warning lamp and applied to the Ignition input terminal 5. The SDM responds by turning on the air bag warning lamp for 3 - 4 seconds. The SDM monitors the lamp driver output by comparing the output state at SIR Indicator terminal 7 to the microprocessor commanded state. DTC 43 sets when the Ignition is above a specified value and the output state does not match the commanded ON state of the lamp driver for 1.25 seconds.

### Conditions for Setting the DTC

• | The Ignition voltage is above a specified value.

• | The voltage measured at the SIR Indicator terminal 6 is above a specified value while the lamp driver is commanded ON.

This test runs during the Initialization and Continuous Monitoring when the Ignition voltage is above a specified value.

### Action Taken When the DTC Sets

• | The SDM attempts to turn ON the AIR BAG warning lamp.

• | The SDM sets a diagnostic trouble code.

### Conditions for Clearing the DTC

Current and History DTC codes must be cleared using a scan tool Clear DTC Information command. If the circuit fault has been successfully repaired and the conditions which caused the DTC to set are no longer existing, the DTC may be cleared using the scan tool. If the output state at the SIR Indicator terminal 6 matches the commanded ON state of the lamp driver, Current DTC 43 will change to a History DTC 43, which may be cleared using the scan tool.

### Diagnostic Aids

These malfunctions are addressed in the SIR Diagnostic System Check via Table C.

### Test Description

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. AIR BAG warning lamp circuitry malfunctions set this DTC. These malfunctions are addressed in the SIR Diagnostic System Check via AIR BAG Warning Lamp Does Not Come On . Failure to properly perform the SIR Diagnostic System Check may result in misdiagnosis.
2. Turn the ignition switch to the ON position.
3. Clear the SIR Diagnostic Trouble Codes.

Is DTC 43 set?

--

Go to Integrity Check

Go to SIR Diagnostic System Check