B0285

DTC B0285

CIRCUIT DESCRIPTION




The body control module (BCM) monitors the voltage level on the supply voltage circuit of the REAR DEFOG relay. The voltage level should be low while the REAR DEFOG relay is de-energized. The voltage will be near system voltage when the BCM energizes the REAR DEFOG relay.

DTC DESCRIPTOR
This diagnostic procedure supports the following DTC:
DTC B0285 Electric Rear Defrost Circuit Low

CONDITIONS FOR RUNNING THE DTC
- The ignition is ON.
- Fog lights are active, if equipped.

CONDITIONS FOR SETTING THE DTC
The BCM detects a low voltage level on the supply circuit of the REAR DEFOG relay when the relay is energized.

ACTION TAKEN WHEN THE DTC SETS
The rear window defogger will be disabled until the condition is no longer present.

CONDITIONS FOR CLEARING THE DTC
- This DTC will change from current to history when the fault is no longer present.
- A history DTC will clear after 100 consecutive ignition cycles if the condition for the malfunction is no longer present.

TEST DESCRIPTION

Steps 1 - 12:

The numbers below refer to the step numbers on the diagnostic table.
2. Listen for an audible click when the REAR DEFOG relay operates. Command both the ON and OFF states. Repeat the commands as necessary.
3. Verifies that the BCM is providing voltage to the REAR DEFOG relay.
5. Tests for a short to ground on the supply voltage circuit of the REAR DEFOG relay coil.