Manual Three Zone Temperature Control
B1058-Recirculation Door Control Circuit/Performance
For a complete wiring diagram, refer to.
Theory of Operation
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: With the ignition on and an actuator movement is commanded by the A/C Heater Control or during an HVAC Actuator Calibration Test.
• Set Condition: If an actuator move is commanded by A/C Heater Control and an overcurrent condition is detected in either clockwise or counterclockwise movement for the period of five seconds. If the A/C Heater Control detects valid current draw for 10 seconds, 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. Refer to => Non-DTC Based
Diagnostics. HVAC Pre-Diagnostic Troubleshooting Procedure
Test Step 1 - CHECK IF DTC IS ACTIVE
• Ignition on, engine not running.
• Using the scan tool, read HVAC DTCs.
Is this DTC active?
Yes
• Go to Test Step 3 => [ Test Step 3 - CHECK THE (C32) RECIRCULATION DOOR DRIVER CIRCUIT FOR
A SHORT TO VOLTAGE ]
No
• Go to Test Step 2 => [ Test Step 2 - PERFORM HVAC ACTUATOR CALIBRATION TEST ]
Test Step 2 - PERFORM HVAC ACTUATOR CALIBRATION TEST
• 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 Test Step 3 => [ Test Step 3 - CHECK THE (C32) RECIRCULATION DOOR DRIVER CIRCUIT FOR
A SHORT TO VOLTAGE ]
No
• Go to Test Step 9 => [ Test Step 9 - CHECK THE WIRING AND CONNECTORS ]
Test Step 3 - CHECK THE (C32) RECIRCULATION DOOR DRIVER CIRCUIT FOR A SHORT TO VOLTAGE
• Turn the ignition off to the lock position.
• Disconnect the A/C Heater Control C1 harness connector.
• Disconnect the Recirculation Door Actuator harness connector.
• Ignition on, engine not running.
• Measure the voltage of the (C32) Recirculation Door Driver circuit.
Is there any voltage present?
Yes
• Repair the (C32) Recirculation Door Driver circuit for a short to voltage.
• Perform the HVAC Verification Test. Refer to => Non-DTC Based Diagnostics. HVAC Verification Test
No
• Go to Test Step 4 => [ Test Step 4 - CHECK THE (C807) COMMON DOOR DRIVER 2 CIRCUIT FOR A
SHORT TO VOLTAGE ]
Test Step 4 - CHECK THE (C807) COMMON DOOR DRIVER 2 CIRCUIT FOR A SHORT TO VOLTAGE
• Measure the voltage of the (C807) Common Door Driver 2 circuit.
Is there any voltage present?
Yes
• Repair the (C807) Common Door Driver 2 circuit for a short to voltage.
• Perform the HVAC Verification Test. Refer to => Non-DTC Based Diagnostics. HVAC Verification Test
No
• Go to Test Step 5 => [ Test Step 5 - CHECK THE (C32) RECIRCULATION DOOR DRIVER CIRCUIT FOR
A SHORT TO GROUND ]
Test Step 5 - CHECK THE (C32) RECIRCULATION DOOR DRIVER CIRCUIT FOR A SHORT TO GROUND
• Turn the ignition off to the lock position.
• Measure the resistance between ground and the (C32) Recirculation Door Driver circuit.
Is the resistance below 100k Ohms?
Yes
• Repair the (C32) Recirculation Door Driver circuit for a short to ground.
• Perform the HVAC Verification Test. Refer to => Non-DTC Based Diagnostics. HVAC Verification Test
No
• Go to Test Step 6 => [ Test Step 6 - CHECK THE (C807) COMMON DOOR DRIVER 2 CIRCUIT FOR A
SHORT TO GROUND ]
Test Step 6 - CHECK THE (C807) COMMON DOOR DRIVER 2 CIRCUIT FOR A SHORT TO GROUND
• Measure the resistance between ground and the (C807) Common Door Driver 2 circuit.
Is the resistance below 100k Ohms?
Yes
• Repair the (C807) Common Door Driver 2 circuit for a short to ground.
• Perform the HVAC Verification Test. Refer to => Non-DTC Based Diagnostics. HVAC Verification Test
No
• Go to Test Step 7 => [ Test Step 7 - CHECK THE RECIRCULATION DOOR ]
Test Step 7 - CHECK THE RECIRCULATION DOOR
• 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. Refer to => Non-DTC Based Diagnostics. HVAC Verification Test
No
• Go to Test Step 8 => [ Test Step 8 - CHECK THE RECIRCULATION DOOR ACTUATOR ]
Test Step 8 - CHECK THE RECIRCULATION DOOR ACTUATOR
• Replace the Recirculation Door Actuator.
• Using the scan tool, erase HVAC DTCs and perform the HVAC Actuator Calibration Test.
Did this DTC reset?
Yes
• Replace and program the A/C Heater Control.
• Perform the HVAC Verification Test. Refer to => Non-DTC Based Diagnostics. HVAC Verification Test
No
• Test complete.
• Perform the HVAC Verification Test. Refer to => Non-DTC Based Diagnostics. HVAC Verification Test
Test Step 9 - CHECK THE WIRING AND CONNECTORS
• The conditions necessary to set the DTC are not present at this time.
• Using the scan tool, check the Environmental Data to help identify the conditions in which the DTC was set.
• 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.
• 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. Refer to => Non-DTC Based Diagnostics. HVAC Verification Test
No
• Test complete.