HVAC

B105C-RECIRCULATION DOOR TRAVEL RANGE TOO SMALL



After the initial installation of the A/C Heater Control, the controller is calibrated to each individual blend/mode door actuator. These calibrations are stored as in the number of pulses it takes to move the door from one stop to another. The A/C Heater Control drives the Door Actuators by the use of Door Driver circuit and a Common Door Driver circuit and monitors all door actuator pulses to detect door movement in both directions. Most of the door actuators share a common door driver circuit but each door actuator has its own unique driver circuit. Due to shared circuitry, similar Diagnostic trouble Codes (DTCs) can set at the same time for multiple actuators depending upon the type of circuit malfunction, its location, and the direction the actuator is moving when the malfunction is present.

- When Monitored:
When ever an Actuator Calibration Test is performed.

- Set Condition:
The A/C Heater Control uses a pulse feedback to the controller to detect the total door movement range. If the amount of pulses required to move the door completely in both directions is less than what the controller has stored in its memory, this DTC will set. If an Actuator Calibration Test is performed and the A/C Heater Control detects a valid range of the door movement span in both directions, 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 FOR RELATED DTCS
1. Ignition on, engine not running.
2. Using the scan tool, read HVAC DTCs.

Are there any Door Control Circuit Open or Door Control Performance DTCs present?

Yes

- Testing and Inspection Perform the appropriate diagnostic procedure.

No

- Go To 2

2. 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 4

No

- Go To 3

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

Did this DTC change from Stored to Active while performing the HVAC Actuator Calibration Test?

Yes

- Go To 4

No

- Go To 6

4. CHECK THE RECIRCULATION DOOR
1. Remove the Recirculation Door Actuator and check the Recirculation Door for binding and full travel.

Were there any problems found?

Yes

- Repair or replace the Recirculation Door as necessary.
- Perform the HVAC VERIFICATION TEST. HVAC Verification Test.

No

- Go To 5

5. CHECK THE RECIRCULATION DOOR ACTUATOR
1. Replace the Recirculation Door Actuator.
2. Using the scan tool, erase HVAC DTCs.
3. Using the scan tool, perform the HVAC Actuator Calibration Test.

Did this DTC reset during HVAC Actuator Calibration Test?

Yes

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

No

- Test complete.

6. 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 schematics as a guide, inspect the wiring and connectors specific to this circuit.
4. Check for an intermittent condition by inspecting the related wiring harness for chafed, pierced, pinched, partially broken wires.
5. Check the connectors for broken, bent, pushed out, spread, corroded, or contaminated terminals.
6. 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.