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. When the rear window defogger switch is depressed. The HVAC control module energizes the heated outside rearview mirror and rear window defogger relay by momentarily supplying battery positive voltage to the to the control circuit of the 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 engine is running. |
| • | The rear window defogger is enabled. |
Conditions for Setting the DTC
A short to ground on the control 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
| • | A history DTC will clear after 20 consecutive ignition cycles if the condition for the fault is no longer present. |
| • | A short to ground on the control circuit of the heated outside rearview mirror and rear window defogger relay is no longer present. |
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 5 | Go to Step 4 |
4 | Test the control circuit of the Heated Outside Rearview Mirror and Rear Window Defogger 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 9 | Go to Step 6 |
5 | 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 9 | Go to Step 7 |
6 | 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 9 | Go to Step 8 |
7 | Replace the Heated Outside Rearview Mirror and Rear Window Defogger relay. Did you complete the replacement? | -- | Go to Step 9 | -- |
8 | Replace the HVAC Control Module. Refer to HVAC Control Module Replacement in HVAC Systems - Automatic. Did you complete the replacement? | -- | Go to Step 9 | -- |
9 |
Does the DTC reset? | -- | Go to Step 2 | System OK |
