For 1990-2009 cars

### Electric Rear Defrost Circuit Low

When the rear defog input circuit 292 to the control body module (BCM) is momentarily switched to ground, as when the rear defog switch is pressed, the BCM will respond by grounding circuit 193, the coil of the rear defog relay.

This action energizes the rear defrost relay providing power to circuit 293, the rear defrost heater elements, circuit 683, the heated mirror relay coil, and circuit 683, the rear defrost LED telltale. Momentarily switching circuit 292 to ground again will result in the BCM turning the rear defrost relay OFF.

The first time in an ignition cycle that the rear defrost is activated, the rear defrost will remain ON for 15 minutes or until the ignition switch is turned OFF. If the rear defrost is activated again during the same ignition cycle, the rear defrost will remain ON for 7 ½ minutes or until the ignition switch is turned OFF.

### DTC Parameters

• | The ignition is in RUN.

• | Circuit 193 is grounded.

• | The BCM is NOT requesting the rear defrost system.

• | The condition exists for 30 seconds.

### Diagnostic Aids

• | Check for a poor connection at the BCM. Inspect the harness connectors for backed out terminals, improper terminal mating, broken connector locks, improperly formed or damaged terminals, and poor terminal to wire connection (terminal crimped over wire insulation and not conductors).

• | Inspect the wiring harness for damage. Check for broken or chaffed insulation.

• | If a fault is suspected to be intermittent, wiggling the harness wiring may help in locating the fault.