Circuit Description
The Body Control Module (BCM) monitors the voltage level on the control circuit of the RR DEFOG relay. The voltage level should be near system voltage while the RR DEFOG relay is de-energized. The voltage will be pulled low when the BCM energizes the RR DEFOG relay. The BCM test the control circuit of the RR DEFOG relay while the relay is energized.
Conditions for Running the DTC
The engine is running.
Conditions for Setting the DTC
The BCM detects a high voltage level on the control circuit of the RR DEFOG relay for 2 seconds.
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 requires an ignition cycle in order to change from current to history. |
| • | The BCM no longer detects a high voltage level on the control circuit of the RR DEFOG relay only with the relay energized. |
| • | A history DTC will clear after 50 consecutive ignition cycles if the condition for the malfunction is no longer present. |
Test Description
The number(s) below refer to the step number(s) on the diagnostic table.
-
Listen for an audible click when the RR DEFOG relay operates. Command both the ON and OFF states. Repeat the commands as necessary.
-
Tests for voltage at the coil side of the RR DEFOG relay. The HVAC fuse supplies power to the coil side of the RR DEFOG relay.
-
Verifies that the BCM is providing ground to the RR DEFOG relay.
-
Tests if ground is constantly being applied to the RR DEFOG relay.
-
Tests for short to voltage on the control circuit of the RR DEFOG relay.
Step | Action | Yes | No |
|---|---|---|---|
Schematic Reference: Defogger Schematics Connector End View Reference: Stationary Windows Connector End Views | |||
1 | Did you perform the Defogger Diagnostic System Check? | Go to Step 2 | |
Do you hear a click when you command the RR DEFOG relay ON and OFF? | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems | Go to Step 3 | |
Does the test lamp illuminate? | Go to Step 4 | Go to Step 10 | |
Does the test lamp turn ON and OFF with each command? | Go to Step 8 | Go to Step 5 | |
Does the test lamp remain illuminated with each command? | Go to Step 7 | Go to Step 6 | |
Test the control circuit of the RR DEFOG relay for short to battery positive voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 13 | Go to Step 9 | |
7 | Test the control circuit of the RR DEFOG relay for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 13 | Go to Step 9 |
8 | Inspect for poor connections at the RR DEFOG relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 13 | Go to Step 11 |
9 | Inspect for poor connections at the harness connector of the BCM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition? | Go to Step 13 | Go to Step 12 |
10 | Repair an open or high resistance in the Ignition 3 voltage circuit of the RR DEFOG relay. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | Go to Step 13 | -- |
11 | Replace the RR DEFOG relay. Did you complete the replacement? | Go to Step 13 | -- |
12 |
Important: Perform the set up procedure for the body control module (BCM). Replace the BCM. Refer to Body Control Module Replacement in Body Control System. Did you complete the replacement? | Go to Step 13 | -- |
13 |
Does the DTC reset? | Go to Step 2 | System OK |
