Theory of Operation
The A/C Heater Control drives the Mode Door 1 (Panel to Floor) Actuator via the (C29) Mode Door 1 Driver circuit
and the (C34) Common Door Driver circuit. All of the door actuators share the (C34) Common Door Driver circuit.
Inside the A/C Heater Control, each door actuator has its own unique driver, but all share a single common door
driver circuit. Note that due to the shared circuitry similar DTCs can set at the same time for multiple actuators
depending upon the type of short, its location, and the direction the actuator is moving when the short is present.
When Monitored:
When the Actuator DTC Detection Test is executed.
Set Condition:
If the (C29) Mode Door 1 Driver circuit is shorted to voltage.
Possible Causes
(C29) MODE DOOR 1 DRIVER CIRCUIT SHORTED TO VOLTAGE
A/C HEATER CONTROL
Diagnostic Test
1.CHECK (C29) MODE DOOR 1 DRIVER CIRCUIT FOR A SHORT TO VOLTAGE
NOTE: If present, diagnose and repair DTC B10AB Right Blend
Door Control Circuit High or B10AA Right Blend Door Control Cir-
cuit Low before proceeding.
Turn the ignition off.
Disconnect the A/C Heater Control C1 harness connector.
Turn the ignition on.
Measure the voltage of the (C29) Mode Door 1 Driver circuit.
Is the voltage above 0.2 volts?
Ye s>>
Repair the (C29) Mode Door 1 Driver circuit for a short to
voltage.
Perform BODY VERIFICATION TEST – VER 1. (Refer to 8
- ELECTRICAL/ELECTRONIC CONTROL MODULES -
STANDARD PROCEDURE).
No>>
Go To 2
2.RUN THE ACTUATOR DTC DETECTION TEST
Turn the ignition off.
Reconnect the A/C Heater Control C1 harness connector.
Turn the ignition on.
With the scan tool in HVAC, select System Tests and then select Actuator DTCDetection. When the test is com-
plete, select View DTCs.
Does the scan tool only display: B1042–PANEL MODE DOOR 1 CONTROL CIRCUIT HIGH?
Ye s>>
Replace the A/C Heater Control in accordance with the Service Information.
Perform BODY VERIFICATION TEST – VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL
MODULES - STANDARD PROCEDURE).
No, Other DTC(s) Displayed
Diagnose and repair the DTC(s). If multiple DTCs are present, beginning with the passenger blend door,
diagnose and repair all short high DTCs and then all short low DTCs. Refer tothe Table of Contents in
this Section for a complete list of HVAC related symptoms.
No, And No Other DTCs Displayed
Using the wiring diagram as a guide, inspect the wiring and connectors for conditions causing an inter-
mittent short. Repair as necessary.
Perform BODY VERIFICATION TEST – VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL
MODULES - STANDARD PROCEDURE).
Theory of Operation
The A/C Heater Control drives the Mode Door 1 (Panel to Floor) Actuator via the (C29) Mode Door 1 Driver circuit
and the (C34) Common Door Driver circuit. All of the door actuators share the (C34) Common Door Driver circuit.
Inside the A/C Heater Control, each door actuator has its own unique driver, but all share a single common door
driver circuit. Note that due to the shared circuitry similar DTCs can set at the same time for multiple actuators
depending upon the type of short, its location, and the direction the actuator is moving when the short is present.
When Monitored:
When the Actuator DTC Detection Test is executed.
Set Condition:
If the (C29) Mode Door 1 Driver circuit is shorted to voltage.
Possible Causes
(C29) MODE DOOR 1 DRIVER CIRCUIT SHORTED TO VOLTAGE
A/C HEATER CONTROL
Diagnostic Test
1.CHECK (C29) MODE DOOR 1 DRIVER CIRCUIT FOR A SHORT TO VOLTAGE
Turn the ignition off.
Disconnect the A/C Heater Control C1 harness connector.
Turn the ignition on.
Measure the voltage of the (C29) Mode Door 1 Driver circuit.
Is the voltage above 0.2 volts?
Ye s>>
Repair the (C29) Mode Door 1 Driver circuit for a short to
voltage.
Perform BODY VERIFICATION TEST – VER 1. (Refer to 8
- ELECTRICAL/ELECTRONIC CONTROL MODULES -
STANDARD PROCEDURE).
No>>
Go To 2
2.RUN THE ACTUATOR DTC DETECTION TEST
Turn the ignition off.
Reconnect the A/C Heater Control C1 harness connector.
Turn the ignition on.
With the scan tool in HVAC, select System Tests and then select Actuator DTCDetection. When the test is com-
plete, select View DTCs.
Does the scan tool only display: B1042–PANEL MODE DOOR 1 CONTROL CIRCUIT HIGH?
Ye s>>
Replace the A/C Heater Control in accordance with the Service Information.
Perform BODY VERIFICATION TEST – VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL
MODULES - STANDARD PROCEDURE).
No, Other DTC(s) Displayed
Diagnose and repair the other DTC(s). If multiple DTCs are present, beginning with the common circuit,
diagnose and repair all short high DTCs and then all short low DTCs. Refer tothe Table of Contents in
this Section for a complete list of HVAC related symptoms.
No, And No Other DTCs Displayed
Using the wiring diagram as a guide, inspect the wiring and connectors for conditions causing an inter-
mittent short. Repair as necessary.
Perform BODY VERIFICATION TEST – VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL
MODULES - STANDARD PROCEDURE).
Theory of Operation
The A/C Heater Control drives the Mode Door 1 (Panel to Floor) Actuator via the (C29) Mode Door 1 Driver circuit
and the (C34) Common Door Driver circuit. All of the door actuators share the (C34) Common Door Driver circuit.
Inside the A/C Heater Control, each door actuator has its own unique driver, but all share a single common door
driver circuit. Note that due to the shared circuitry similar DTCs can set at the same time for multiple actuators
depending upon the location of the open circuit and the direction the actuator is moving when the open is present.
When Monitored:
During actuator calibration.
Set Condition:
If the Mode Door 1 (Panel to Floor) Actuator’s electrical circuit is open. This DTC has a maturing time of 5
seconds and a de-maturing time of 10 seconds. If the DTC’s status changes from active to stored it will stay
in memory for 100 ignition cycles.
Possible Causes
(C29) MODE DOOR 1 DRIVER CIRCUIT OPEN
(C34) COMMON DOOR DRIVER CIRCUIT OPEN
MODE DOOR 1 (PANEL TO FLOOR) ACTUATOR
A/C HEATER CONTROL
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 for stored DTC test procedures.
Diagnostic Test
1.CHECK FOR ACTIVE CONTROL CIRCUIT/PERFORMANCE DTCs
Turn the ignition on.
With the scan tool, read active HVAC DTCs.
Does the scan tool display any active: XXXX CONTROL CIRCUIT/PERFORMANCE DTCs?
Ye s>>
Diagnose and repair the DTC(s). Refer to the Table of Contents in this Section for a complete list of
HVAC related symptoms.
No>>
Go To 2
2.CHECK MODE DOOR 1 (PANEL TO FLOOR) ACTUATOR CIRCUIT RESISTANCE
Turn the ignition off.
Disconnect the A/C Heater Control C1 harness connector.
Measure the resistance between the (C29) Mode Door 1 Driver circuit
and the (C34) Common Door Driver circuit in the A/C Heater Control C1
harness connector.
Is the resistance above 70 ohms?
Ye s>>
Go To 3
No>>
Replace the A/C Heater Control in accordance with the Ser-
vice Information.
Perform BODY VERIFICATION TEST – VER 1. (Refer to 8
- ELECTRICAL/ELECTRONIC CONTROL MODULES -
STANDARD PROCEDURE).
Theory of Operation
The A/C Heater Control drives the Mode Door 1 (Panel to Floor) Actuator via the (C29) Mode Door 1 Driver circuit
and the (C34) Common Door Driver circuit. All of the door actuators share the (C34) Common Door Driver circuit.
Inside the A/C Heater Control, each door actuator has its own unique driver, but all share a single common door
driver circuit. Note that due to the shared circuitry similar DTCs can set at the same time for multiple actuators
depending upon the location of the open circuit and the direction the actuator is moving when the open is present.
When Monitored:
During actuator calibration.
Set Condition:
If the Mode Door 1 (Panel to Floor) Actuator’s electrical circuit is open. This DTC has a maturing time of 5
seconds and a de-maturing time of 10 seconds. If the DTC’s status changes from active to stored it will stay
in memory for 100 ignition cycles.
Possible Causes
(C29) MODE DOOR 1 DRIVER CIRCUIT OPEN
(C34) COMMON DOOR DRIVER CIRCUIT OPEN
MODE DOOR 1 (PANEL TO FLOOR) ACTUATOR
A/C HEATER CONTROL
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 for stored DTC test procedures.
Diagnostic Test
1.CHECK FOR ACTIVE CONTROL CIRCUIT/PERFORMANCE DTCs
Turn the ignition on.
With the scan tool, read active HVAC DTCs.
Does the scan tool display any active: XXXX CONTROL CIRCUIT/PERFORMANCE DTCs?
Ye s>>
Diagnose and repair the DTC(s). Refer to the Table of Contents in this Section for a complete list of
HVAC related symptoms.
No>>
Go To 2
2.CHECK MODE DOOR 1 (PANEL TO FLOOR) ACTUATOR CIRCUIT RESISTANCE
Turn the ignition off.
Disconnect the A/C Heater Control C1 harness connector.
Measure the resistance between the (C29) Mode Door 1 Driver circuit
and the (C34) Common Door Driver circuit in the A/C Heater Control C1
harness connector.
Is the resistance above 70 ohms?
Ye s>>
Go To 3
No>>
Replace the A/C Heater Control in accordance with the Ser-
vice Information.
Perform BODY VERIFICATION TEST – VER 1. (Refer to 8
- ELECTRICAL/ELECTRONIC CONTROL MODULES -
STANDARD PROCEDURE).
B1044–PANEL MODE DOOR 1 TRAVEL RANGE TOO SMALL
For a complete wiring diagramRefer to Section 8W.
Theory of Operation
The A/C Heater Control calibrates each actuator individually. Automaticcalibration occurs upon power up after
installing a new A/C Heater Control. Manual calibration occurs by sendinga command with the scan tool. The pur-
pose of actuator calibration is to determine the total span of door travel between physical stops. To calibrate the
actuator, the A/C Heater Control first moves the door to an end stop, and then counts the number of pulses it takes
to move the door to its other stop. An expected range of span is stored in the control’s memory. If the measured
calibration value is less than the expected range for this actuator, this DTC will set. Note thatthe control clears all
stored calibration faults at the beginning of the calibration procedure.
When Monitored:
During actuator calibration.
Set Condition:
If the total span of the Mode 1 (Panel to Floor) Door is less than the low rangelimit.
Possible Causes
DOOR DRIVER ELECTRICAL CIRCUIT(S)
MODE 1 (PANEL TO FLOOR) DOOR SEIZED, BINDING, OBSTRUCTED
MODE DOOR 1 (PANEL TO FLOOR) ACTUATOR
A/C HEATER CONTROL
Diagnostic Test
1.CHECK FOR ACTIVE CONTROL CIRCUIT/PERFORMANCE DTCs
Turn the ignition on.
With the scan tool, read active HVAC DTCs.
Does the scan tool display any active: XXXX CONTROL CIRCUIT/PERFORMANCE DTCs?
Ye s>>
Diagnose and repair the DTC(s). Refer to the Table of Contents in this Section for a complete list of
HVAC related symptoms.
No>>
Go To 2
2.CHECK FOR ACTIVE CONTROL CIRCUIT OPEN DTCs
With the scan tool, read active HVAC DTCs.
Does the scan tool display any active: XXXX CONTROL CIRCUIT OPEN DTCs?
Ye s>>
Diagnose and repair the DTC(s). Refer to the Table of Contents in this Section for a complete list of
HVAC related symptoms.
No>>
Go To 3
3.RUN THE ACTUATOR DTC DETECTION TEST
With the scan tool in HVAC, select System Tests and then select Actuator DTCDetection. When the test is com-
plete, select View DTCs.
Does the scan tool display any DTCs?
Yes, Dual-Zone System
Diagnose and repair the DTC(s). If multiple DTCs are present, beginning with the passenger blend door,
diagnose and repair all short high DTCs and then all short low DTCs. Refer tothe Table of Contents in
this Section for a complete list of HVAC related symptoms.
Yes, Single-Zone System
>>
Diagnose and repair the DTC(s). If multiple DTCs are present, beginning with the common circuit, diag-
nose and repair all short high DTCs first and then all short low DTCs. Refer to the Table of Contents in
this Section for a complete list of HVAC related symptoms.
No>>
Go To 4
4.INSPECT ACTUATOR & HOUSING ASSEMBLY FOR A CONDITION CAUSING THE DOOR TO SEIZE OR
BIND
Turn the ignition off.
Inspect the actuator, linkage, and housing assembly for a condition causing the door to seize or bind.
Are there any physical or mechanical problems with the door, housing, linkage, or actuator?
Ye s>>
Repair as necessary in accordance with the Service Information.
Perform BODY VERIFICATION TEST – VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL
MODULES - STANDARD PROCEDURE).
No>>
Go To 5
5.CHECK MODE 1 (PANEL TO FLOOR) DOOR TRAVEL
Remove the Mode Door 1 (Panel to Floor) Actuator from the A/C Heater HousingAssembly.
By hand, attempt to rotate the door in both directions. The door should operate smoothly in both directions over
approximately 70 degrees of travel.
Does the door operate smoothly in both directions over approximately 70 degrees of travel?
Ye s>>
Replace the Mode Door 1 (Panel to Floor) Actuator in accordance with the Service Information. Then,
Go To 6.
No>>
Repair as necessary in accordance with the Service Information.
Perform BODY VERIFICATION TEST – VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL
MODULES - STANDARD PROCEDURE).
6.RUN ACTUATOR CALIBRATION TEST
Turn the ignition on.
With the scan tool, select System Tests and then select Actuator Calibration Test. When the test is complete, select
View DTCs.
Does the scan tool display: B1044–PANEL MODE DOOR 1 TRAVEL RANGE TOO SMALL?
Ye s>>
Replace the A/C Heater Control in accordance with the Service Information.
Perform BODY VERIFICATION TEST – VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL
MODULES - STANDARD PROCEDURE).
No>>
Perform BODY VERIFICATION TEST – VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL
MODULES - STANDARD PROCEDURE).