B0283

DTC B0283

CIRCUIT DESCRIPTION
The body control module (BCM) monitors the voltage level on the control circuit of the DEFOG relay. The voltage level should be near system voltage while the DEFOG relay is de-energized. The voltage will be pulled low when the BCM energizes the DEFOG relay. The BCM tests the control circuit of the DEFOG relay every 125 milliseconds.

DTC DESCRIPTOR
This diagnostic procedure supports the following DTC:
DTC B0283 Electric Rear Defrost Circuit

CONDITIONS FOR RUNNING THE DTC
The ignition is ON.

CONDITIONS FOR SETTING THE DTC
One of the following conditions will cause this DTC to set:
- The BCM detects a high voltage level on the control circuit of the DEFOG relay, while the relay is energized.
- The BCM detects a low voltage level or an open on the control circuit of the DEFOG relay, while the relay is not energized.

CONDITIONS FOR CLEARING THE DTC
- A current DTC clears when the malfunction is no longer present.
- A history DTC clears when the module ignition cycle counter reaches the reset threshold, without a repeat of the malfunction.

TEST DESCRIPTION

Step 1 - Step 12:

The numbers below refer to the step numbers on the diagnostic table.
2. This step tests for voltage at the coil side of the DEFOG relay. The HVAC fuse supplies power to the coil side of the DEFOG relay.
3. This step verifies that the BCM is providing ground to the DEFOG relay.
4. This step tests if ground is constantly being applied to the DEFOG relay.
5. This step tests for an open on the control circuit of the DEFOG relay.