B101E

B101E-19-REAR WINDOW DEFROST - OVER CURRENT

For a complete wiring diagram, refer to the Wiring Information.

Theory of Operation

The Body Control Module (BCM) receives the input from the Upper Switch Bank indicating that the rear defogger is requested. The BCM provides a ground path through the rear window defogger control output circuit. The rear window defogger control output circuit connects to the Rear Window Defogger Relay, which when energized provides battery voltage to the Rear Window Defogger, which is also known as Electric Back Light. The Rear Window Defogger Relay is located in the Power Distribution Center. For additional information on the Rear Window Defogger operation, Heated Glass - Operation.

- When Monitored:
With the ignition on.

With the rear window defogger active.

- Set Condition:
When the Body Control Module (BCM) detects higher than expected current on the (C15) Rear Window Defogger Control Output circuit.





1. CHECK FOR AN INTERMITTENT CONDITION
1. Turn the ignition on.
2. With the scan tool, clear all DTCs.
3. Turn the Rear Window Defogger on.
4. With the scan tool, read DTCs.

Does the scan tool display this DTC as active?

Yes

- Go To 2

No

- Test complete, the condition or conditions that originally set this DTC are not present at this time. Using the wiring diagrams as a guide, check all related splices and connectors for signs of water intrusion, corrosion, pushed out or bent terminals, and correct pin tension.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

2. CHECK THE REAR WINDOW DEFOGGER RELAY
1. Turn the Rear Window Defogger off.
2. Turn the ignition off.
3. Remove the Rear Window Defogger Relay and substitute it with a known good relay.
4. Turn the ignition on.
5. Turn the Rear Window Defogger on.
6. With the scan tool, read DTCs.

Does the scan tool display DTC: B101E-19-REAR WINDOW DEFROST - OVER CURRENT?

Yes

- Go To 3

No

- Replace the Rear Window Defogger Relay.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

3. CHECK THE (C15) REAR WINDOW DEFOGGER CONTROL OUTPUT CIRCUIT FOR A SHORT TO VOLTAGE
1. Turn the ignition off.
2. Remove the Rear Window Defogger Relay.
3. Disconnect the BCM C1 harness connector.
4. Turn the ignition on.
5. Measure the voltage between ground and the (C15) Rear Window Defogger Control Output circuit.

Is there any voltage present?

Yes

- Repair the short to voltage in the (C15) Rear Window Defogger Control Output circuit.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Replace the Body Control Module (BCM). Body Control Module - Removal.
- Perform the BODY VERIFICATION TEST. Body Verification Test.