B106B

B106B-REAR DEFROST CONTROL CIRCUIT LOW



Theory of Operation

When the Rear Defogger Button is pressed, the A/C Heater control sends a signal to the Totally Integrated Power Module (TIPM) through the CAN C Interior bus. When the TIPM receives the Rear Defrost On Signal from the A/C Heater Control, the TIPM sends voltage to the Rear Window Defogger through the (C15) Rear Window Defogger Control Output circuit.

- When Monitored:
With ignition on.

- Set Condition:
If the Rear Window Defogger output in the A/C Heater Control turned off and the TIPM detects the (C15) Rear Window Defogger control circuit is either shorted to ground or open.





NOTE: This DTC must be active for the results of this test to be valid. Do not perform this test if this DTC is stored. Refer to HVAC System Test (ATC) for stored DTC test procedures ATC.

1. CHECK (C15) REAR WINDOW DEFOGGER CONTROL CIRCUIT FOR A SHORT TO GROUND
1. Turn the ignition off.
2. Disconnect the TIPM C5 harness connector.
3. Measure the resistance between ground and the (C15) Rear Window Defogger Control circuit in the TIPM C5 harness connector.

Is the resistance above 10k ohms?

Yes

- Go To 2

No

- Repair the (C15) Rear Window Defogger Control circuit for a short to ground.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

2. CHECK (C15) REAR WINDOW DEFOGGER CONTROL CIRCUIT FOR AN OPEN
1. Disconnect the C314 (BODY SIDE) harness connector.
2. Measure the resistance of the (C15) Rear Window Defogger Control circuit between the C314 (BODY SIDE) harness connector and the TIPM C5 harness connector.

Is the resistance below 5.0 ohms?

Yes

- Go To 3

No

- Repair the (C15) Rear Window Defogger Control circuit for an open.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

3. CHECK (C15) REAR WINDOW DEFOGGER CONTROL CIRCUIT FOR VOLTAGE

NOTE: The test light must illuminate brightly. Compare the brightness to that of a direct connection to the battery.

1. Reconnect the TIPM C5 harness connector.
2. Turn the ignition on.
3. Turn the Rear Window Defogger on.
4. Measure the voltage of the (C15) Rear Window Defogger Control in the C314 (BODY SIDE) harness connector.

Does the test tight illuminate brightly?

Yes

- Check the Liftgate Harness for kinked, broken or pinched wires between the C314 (LIFTGATE SIDE) harness connector and the Rear Window Defogger connector, and repair any obvious problems. If OK, replace the Liftgate Window Glass.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Replace the Totally Integrated Power Module.
- Perform the BODY VERIFICATION TEST. Body Verification Test.