Theory of Operation
The A/C Heater Control drives the Left Blend Door Actuator via the (C61) Blend Door 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 sharea single common door driver circuit. 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 Left Blend Door Actuator’s electrical circuit is open. This DTC has a maturingtimeof5secondsandade-
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
(C61) BLEND DOOR DRIVER CIRCUIT OPEN
(C34) COMMON DOOR DRIVER CIRCUIT OPEN
LEFT BLEND DOOR 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 LEFT BLEND DOOR ACTUATOR CIRCUIT RESISTANCE
Turn the ignition off.
Disconnect the A/C Heater Control C1 harness connector.
Measure the resistance between the (C61) Blend Door 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).
B10A6–LEFT BLEND DOOR TRAVEL RANGE TOO SMALL (DUAL-ZONE)
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 Left Blend Door is less than the low range limit.
Possible Causes
DOOR DRIVER ELECTRICAL CIRCUIT(S)
LEFT BLEND DOOR SEIZED, BINDING, OBSTRUCTED
LEFT BLEND DOOR 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?
Ye s>>
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>>
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 LEFT BLEND DOOR TRAVEL
Remove the Left Blend Door Actuator from the A/C Heater Housing Assembly.
By hand, attempt to rotate the door in both directions. The door should operate smoothly in both directions over
approximately 53 degrees of travel.
Does the door operate smoothly in both directions over approximately 53 degrees of travel?
Ye s>>
Replace the Left Blend Door 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: B10A6–LEFT BLEND DOOR 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).
B10A7–LEFT BLEND DOOR TRAVEL RANGE TOO LARGE (DUAL-ZONE)
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 exceeds the expected range for this actuator, this DTC will set. Note that the 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 Left Blend Door exceeds the high range limit.
Possible Causes
DOOR DRIVER ELECTRICAL CIRCUIT(S)
LEFT BLEND DOOR OR A/C HEATER HOUSING COMPONENTS WARPED, WORN, DAMAGED, MISSING,
BROKEN
LEFT BLEND DOOR 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?
Ye s>>
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>>
Go To 4
4.CHECK FOR A BROKEN LEFT BLEND DOOR ACTUATOR
Turn the ignition off.
Remove the Left Blend Door Actuator from the A/C Heater Housing Assembly.
By hand, attempt to rotate the actuator in both directions.
Does the actuator turn in either direction?
Ye s>>
Replace the Left Blend Door Actuator 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 LEFT BLEND DOOR & A/C HEATER HOUSING FOR WARPED, WORN, DAMAGED, MISSING, &
BROKEN COMPONENTS
Inspect for excessively worn, disconnected, missing, or broken door linkage. Inspect for a damaged or broken A/C
Heater Housing Assembly. Inspect for a warped or broken door, and missing door seals. Rotate the door from stop
to stop. The door should rotate approximately 53 degrees.
Are there any physical or mechanical problems with the door or housing?
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>>
Replace the Left Blend Door Actuator in accordance with the Service Information. Then, Go To 6.
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: B10A7–LEFT BLEND DOOR TRAVEL RANGE TOO LARGE?
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).
B10A9–RIGHT BLEND DOOR CONTROL CIRCUIT/PERFORMANCE (DUAL-ZONE)
For a complete wiring diagramRefer to Section 8W.
Theory of Operation
The A/C Heater Control monitors the door driver circuits during actuator operation for shorts to ground, shorts to
battery, and shorts to other door driver circuits. If detected, the A/C Heater Control reports these types of faults as
Control Circuit/Performance DTCs. It is important to note that Control Circuit/Performance DTCs do not indicate
where or what type of short is present and that additional system testing isnecessary to provide more details about
the reported fault.
When Monitored:
When actuator movement is requested.
Set Condition:
If the A/C Heater Control detects an excessive current draw on any of the door driver circuits while attempting
to drive this actuator. 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
DOOR DRIVER CIRCUIT(S) SHORTED
NOTE:TheDTCmustbeactivefortheresultsofthistesttobevalid.Donotperform this test if the DTC is
stored. Refer to HVAC System Test for stored DTC test procedures.
Diagnostic Test
1.RUN THE ACTUATOR DTC DETECTION TEST
Turn the ignition on.
With the scan tool in HVAC, erase DTCs.
With the scan tool, select System Tests and then select Actuator DTC Detection. When the test is complete, select
View DTCs.
Repair
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.
When Monitored:
With the ignition on. Battery voltage greater than 10.4 volts.
Set Condition:
If the Totally Integrated Power Module (TIPM) detects a shorted low condition in the (C123) Condenser Fan
Control circuit.
Possible Causes
(C123) CONDENSER FAN CONTROL OUTPUT CIRCUIT SHORTED TO GROUND
CONDENSER FAN MOTOR
TIPM
Diagnostic Test
1.VERIFY DTC IS ACTIVE
Turn the ignition on.
With the scan tool, erase TIPM DTCs.
Turn the ignition off, wait 10 seconds, and turn the ignition on.
With the scan tool, actuate the Condenser Fan.
With the scan tool, read TIPM DTCs.
Does this DTC reset?
Ye s>>
With the scan tool, de-actuate the Condenser Fan. Then, Go To 2
No>>
With the scan tool, de-actuate the Condenser Fan. Then, check for an intermittent condition by inspect-
ing the related wiring harness for chafed, pierced, pinched, and partially broken wires. Also, inspect the
related connectors for broken, bent, corroded, and contaminated terminals.
Perform BODY VERIFICATION TEST – VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL
MODULES - STANDARD PROCEDURE).
2.CHECK (C123) CONDENSER FAN CONTROL OUTPUT CIRCUIT FOR A SHORT TO GROUND
Turn the ignition off.
Disconnect the TIPM C8 harness connector.
Disconnect the Condenser Fan Motor harness connector.
Measure the resistance of the (C123) Condenser Fan Control Output
circuit between ground and the Condenser Fan Motor harness connec-
tor.
Istheresistancebelow100ohms?
Ye s>>
Repair the (C123) Condenser Fan Control Output circuit for
a short to ground.
Perform BODY VERIFICATION TEST – VER 1. (Refer to 8
- ELECTRICAL/ELECTRONIC CONTROL MODULES -
STANDARD PROCEDURE).
No>>
Go To 3
3.CHECK FOR A SHORTED CONDENSER FAN MOTOR
Reconnect the TIPM C8 harness connector.
Ignition on, engine not running.
With the scan tool, actuate the Condenser Fan.
Using a 12-volt test light connected to ground, probe the (C123) Con-
denser Fan Control Output circuit at the Condenser Fan Motor harness
connector.
Does the test light illuminate brightly and flash on and off?
Ye s>>
With the scan tool, de-actuate the Condenser Fan. Then,
replace the Condenser Fan Motor in accordance with the
Service Information.
Perform BODY VERIFICATION TEST – VER 1. (Refer to 8
- ELECTRICAL/ELECTRONIC CONTROL MODULES -
STANDARD PROCEDURE).
No>>
With the scan tool, de-actuate the Condenser Fan. Then,
Go To 4
4.INSPECT RELATED WIRING
NOTE: Before continuing, check the TIPM harness connector terminals for corrosion, damage, or terminal
push out. Repair as necessary.
Turn the ignition off.
Using the schematics as a guide, inspect the related wiring harness and connectors.
Pay particular attention to all Power and Ground circuits.
Were any problems found?
Ye s>>
Repair as necessary.
Perform BODY VERIFICATION TEST – VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL
MODULES - STANDARD PROCEDURE).
No>>
Replace the TIPM in accordance with the Service Information.
Perform the BODY VERIFICATION TEST – VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CON-
TROL MODULES - STANDARD PROCEDURE)