For 1990-2009 cars
Stationary Windows Components
Rear Defogger Relay and Radio Antenna Amplifier
Outside Rearview Mirror Schematics

### Circuit Description

The heater and A/C control module provides between 6-8 Volts to the control circuit of the heated outside rearview mirror and rear window defogger relay. The heater and A/C 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 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
--- | --- | --- | --- | ---
1 | Did you perform the Stationary Windows Diagnostic System Check? | -- | Go to Step 2 | Go to Diagnostic System Check - Stationary Windows
2 |

1. Start the engine.
2. Depress the rear window defogger switch.
3. Observe the rear window defogger indicator on the Heater and A/C Control Module.

Does the rear window defogger indicator illuminate?

--

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

Go to Step 3

3 |

1. Disconnect the Heated Outside Rearview Mirror and Rear Window Defogger relay.
2. Turn ON the ignition, with the engine OFF.
3. Measure the voltage from the control circuit of the Heated Outside Rearview Mirror and Rear Window Defogger relay to a good ground.

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 Heater and A/C 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 Heater and A/C Control Module. Refer to Control Assembly Replacement in HVAC Systems - Automatic. Did you complete the replacement? | -- | Go to Step 11 | --
11 |

1. Use the scan tool in order to the DTCs.
2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

--

Go to Step 2

System OK