9000 - 9999: 9079

9079-WINDSHIELD HEATER CONTROL CIRCUIT HIGH - BCM





For a complete wiring diagram refer to Diagrams/Electrical

- When Monitored:

Continuously.

- Set Condition:

If the voltage detected by the BCM on the Heated Windshield Relay Control circuit is other than expected.






Diagnostic Test

1. ERASE AND ATTEMPT TO RESET DTC

Turn the ignition on.

With the scan tool, record and erase the current Body Control Module DTC's.

Start the engine.

Operate the heated windshield switch several time.

With the scan tool, read the current Body Control Module DTC's.

Does the scan tool display: 9079-WINDSHIELD HEATER CONTROL CIRCUIT HIGH?

Yes

- Go To 2

No

- The condition that caused this symptom is currently not present. Inspect the related wiring harness for a possible intermittent condition.
- Perform BODY VERIFICATION TEST - VER 1. Verification Tests


2. INSTALL KNOWN GOOD RELAY

Turn the ignition off.

Substitute the original Heated Windshield Relay with a known good relay.

Turn the ignition on.

With the scan tool, erase the current Body Control Module DTCs.

Start the engine.

Operate the Heated Windshield switch several times.

With the scan tool, read the current Body Control Module DTC's.

Does the scan tool display: 9079-WINDSHIELD HEATER CONTROL CIRCUIT HIGH?

Yes

- Go To 3

No

- Replace the original Heated Windshield Relay.
- Perform BODY VERIFICATION TEST - VER 1. Verification Tests


3. OPEN GROUND CIRCUIT

Turn the ignition off.

Disconnect the Heated Windshield Relay.

Measure the resistance of the Ground circuit at the Heated Windshield Relay connector.

Is the resistance above 3.0 ohms?

Yes

- Repair the open relay Ground circuit.
- Perform BODY VERIFICATION TEST - VER 1. Verification Tests

No

- Go To 4


4. HEATED WINDSHIELD RELAY CONTROL CIRCUIT SHORT TO VOLTAGE

Turn the ignition off.

Disconnect the Heated Windshield Relay.

Disconnect the Body Control Module C9 connector.

Measure the voltage of the Heated Windshield Relay Control circuit at the relay connector to ground.

Turn the ignition On.

Is the voltage above 1.0 volt?

Yes

- Repair the Heated Windshield Relay Control circuit for a short to voltage.
- Perform BODY VERIFICATION TEST - VER 1. Verification Tests

No

- Go To 5


5. HEATED WINDSHIELD RELAY CONTROL CIRCUIT OPEN

Turn the ignition off.

Measure the resistance of the Heated Windshield Relay Control circuit between the BCM connector and the relay connector.

Is the resistance below 5.0 ohms?

Yes

- Replace the Body Control Module.
- Perform BODY VERIFICATION TEST - VER 1. Verification Tests

No

- Repair the Heated Windshield Relay Control circuit for an open.
- Perform BODY VERIFICATION TEST - VER 1. Verification Tests