Circuit Description
The HVAC control module provides between 6-8 volts to the control circuit of the heated outside rearview mirror and rear window defogger relay. The HVAC control module tests the control circuit of the heated outside rearview mirror and rear window defogger relay every 150 milliseconds.
Conditions for Running the DTC
| • | The ignition is ON. |
| • | The rear window defogger is not enabled. |
Conditions for Setting the DTC
One of the following conditions can cause this DTC to set:
| • | An open or short to battery positive voltage on the control circuit of the heated outside rearview mirror and rear window defogger relay. |
| • | An open or high resistance on the ground circuit of the heated outside rearview mirror and rear window defogger relay. |
Action Taken When the DTC Sets
The rear window defogger is disabled.
Conditions for Clearing the DTC
The DTC will clear from current status when one of the following conditions is no longer present:
| • | A history DTC will clear after 20 consecutive ignition cycles if the condition for the fault is no longer present. |
| • | An open or short to battery positive voltage on the control circuit of the heated outside rearview mirror and rear window defogger relay. |
| • | An open or high resistance on the ground circuit of the heated outside rearview mirror and rear window defogger relay. |
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
Schematic Reference: Defogger Schematics | ||||
1 | Did you perform the Stationary Windows Diagnostic System Check? | -- | Go to Step 2 | |
2 |
Does the rear window defogger indicator illuminate? | -- | Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems | Go to Step 3 |
3 |
Does the voltage measure within the specified range? | 6-8 V | Go to Step 4 | Go to Step 5 |
4 | Measure the resistance from the ground circuit of the Heated Outside Rearview Mirror and Rear Window Defogger relay coil to a good ground. Is the resistance within the specified range? | 1-3 ohms | Go to Step 6 | Go to Step 8 |
5 | Test the control circuit of the Heated Outside Rearview Mirror and Rear Window Defogger relay for an open or 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 11 | Go to Step 7 |
6 | Inspect for a poor connection at the Heated Outside Rearview Mirror and Rear Window Defogger 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 11 | Go to Step 9 |
7 | Inspect for a poor connection at the harness connector of the HVAC Control Module. 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 11 | Go to Step 10 |
8 | Repair an open or high resistance in the ground circuit of the Heated Outside Rearview Mirror and Rear Window Defogger relay coil. Refer to Wiring Repairs in Wiring Systems. Did you complete the repair? | -- | Go to Step 11 | -- |
9 | Replace the Heated Outside Rearview Mirror and Rear Window Defogger relay. Did you complete the replacement? | -- | Go to Step 11 | -- |
10 | Replace the HVAC Control Module. Refer to HVAC Control Module Replacement in HVAC Systems - Automatic. Did you complete the replacement? | -- | Go to Step 11 | -- |
11 |
Does the DTC reset? | -- | Go to Step 2 | System OK |
