B11CE-92

B11CE-92-REAR TEMPERATURE DOOR CONTROL - PERFORMANCE OR INCORRECT OPERATION





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

Theory of Operation

The rear mode and temperature blend doors are controlled by a two wire actuator. The door actuator motor will rotate either clockwise or counter clockwise by reversing the polarity of the circuits depending on the command from the controller. The A/C Heater Control monitors the circuits for proper operation and will set a Diagnostic Trouble Code (DTC) if a fault is detected. For further information Blend Door Actuator - Operation.

- When Monitored:
Continuously with the ignition on.

- Set Condition:
The A/C Heater Control detects no feedback pulses on the Rear Blend Door control circuit for 15 seconds or more. If the A/C Heater Control detects a valid feedback pulse, the DTC will change from Active to Stored and will stay in the controllers memory for 100 ignition cycles.





Always perform the HVAC Pre-Diagnostic Troubleshooting procedure before proceeding. HVAC Pre-Diagnostic Troubleshooting Procedure.

1. CHECK IF DTC IS ACTIVE
1. Ignition on, engine not running.
2. Using the scan tool, read HVAC DTCs.

Is this DTC active?

Yes

- Go To 2

No

- Go To 9

2. PERFORM HVAC ACTUATOR CALIBRATION TEST
1. Using the scan tool, perform the HVAC Actuator Calibration Test.

Did any other HVAC DTCs set while performing the Actuator Calibration Test?

Yes

- Testing and Inspection Perform the appropriate diagnostic procedure.

No

- Go To 3

3. CHECK THE (C59) REAR BLEND DOOR DRIVER CIRCUIT FOR A SHORT TO VOLTAGE




1. Turn the ignition off to the lock position.
2. Disconnect the A/C Heater Control C1 and C2 harness connectors.
3. Disconnect the Rear Blend Door Actuator harness connector.
4. Ignition on, engine not running.
5. Measure the voltage of the (C59) Rear Blend Door Driver circuit.

Is there any voltage present?

Yes

- Repair the (C59) Rear Blend Door Driver circuit for a short to voltage.
- Perform the HVAC VERIFICATION TEST. HVAC Verification Test.

No

- Go To 4

4. CHECK THE (C60) REAR BLEND DOOR COMMON DRIVER CIRCUIT FOR A SHORT TO VOLTAGE




1. Measure the voltage of the (C60) Rear Blend Door Common Driver circuit.

Is there any voltage present?

Yes

- Repair the (C60) Rear Blend Door Common Driver circuit for a short to voltage.
- Perform the HVAC VERIFICATION TEST. HVAC Verification Test.

No

- Go To 5

5. CHECK THE (C59) REAR BLEND DOOR DRIVER CIRCUIT FOR A SHORT TO GROUND




1. Turn the ignition off to the lock position.
2. Measure the resistance between ground and the (C59) Rear Blend Door Driver circuit.

Is the resistance below 100k Ohms?

Yes

- Repair the (C59) Rear Blend Door Driver circuit for a short to ground.
- Perform the HVAC VERIFICATION TEST. HVAC Verification Test.

No

- Go To 6

6. CHECK THE (C60) REAR BLEND DOOR COMMON DRIVER CIRCUIT FOR A SHORT TO GROUND




1. Measure the resistance between ground and the (C60) Rear Blend Door Common Driver circuit.

Is the resistance below 100k Ohms?

Yes

- Repair the (C60) Rear Blend Door Common Driver circuit for a short to ground.
- Perform the HVAC VERIFICATION TEST. HVAC Verification Test.

No

- Go To 7

7. CHECK THE REAR BLEND DOOR
1. Remove the Rear Blend Door Actuator and check the Rear Blend Door for binding and full travel. Blend Door Actuator - Operation.

Were there any problems found?

Yes

- Repair or replace the Rear Blend Door as necessary. Rear HVAC Housing.
- Perform the HVAC VERIFICATION TEST. HVAC Verification Test.

No

- Go To 8

8. CHECK THE REAR BLEND DOOR ACTUATOR
1. Replace the Rear Blend Door Actuator. Blend Door Actuator - Operation.
2. Using the scan tool, erase HVAC DTCs and perform the HVAC Actuator Calibration Test.
3. With the scan tool, read HVAC DTCs.

Did this DTC reset?

Yes

- Replace and program the A/C Heater Control. A/C And Heater Control - Removal.
- Perform the HVAC VERIFICATION TEST. HVAC Verification Test.

No

- Test complete.
- Perform the HVAC VERIFICATION TEST. HVAC Verification Test.

9. CHECK THE WIRING AND CONNECTORS
1. The conditions necessary to set the DTC are not present at this time.
2. Using the scan tool, check the Environmental Data to help identify the conditions in which the DTC was set.
3. 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.
4. Wiggle the wiring and connectors while checking for shorted and open circuits.

Were there any problems found?

Yes

- Repair as necessary.
- Perform the HVAC VERIFICATION TEST. HVAC Verification Test.

No

- Test complete.