B104C–BLEND DOOR CONTROL CIRCUIT/PERFORMANCE (SINGLE-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:
With the ignition on.
Set Condition:
If the A/C Heater Control detects a short on any of the door driver circuits while attempting to drive this actua-
tor. 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.
Turn the ignition off, wait 10 seconds, and then turn the ignition on.
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 common circuits, diag-
nose and repair all short high DTCs and then all short low DTCs. Refer to the Table of Contents in this
Section for a complete list of HVAC related symptoms.
Theory of Operation
The A/C Heater Control drives the Blend Door Actuator via the (C61) Blend Door Driver circuit and the (C34) Com-
mon 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. 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 (C61) Blend Door Driver circuit is shorted to ground.
Possible Causes
(C61)BLENDDOORDRIVERCIRCUITSHORTEDTOGROUND
(C61) BLEND DOOR DRIVER CIRCUIT SHORTED TO OTHER DOOR DRIVER CIRCUIT(S)
BLEND DOOR ACTUATOR
A/C HEATER CONTROL
Diagnostic Test
1.CHECK (C61) BLEND DOOR DRIVER CIRCUIT FOR A SHORT TO GROUND
Turn the ignition off.
Disconnect the A/C Heater Control C1 harness connector.
Measure the resistance of the (C61) Blend Door Driver circuit between
ground and the A/C Heater Control C1 harness connector.
Istheresistancebelow10kohms?
Ye s>>
Repair the (C61) Blend Door Driver circuit for a short to
ground.
Perform BODY VERIFICATION TEST – VER 1. (Refer to 8
- ELECTRICAL/ELECTRONIC CONTROL MODULES -
STANDARD PROCEDURE).
No>>
Go To 2
4.CHECK (C61) BLEND DOOR DRIVER CIRCUIT FOR A SHORT TO (C34) COMMON DOOR DRIVER
CIRCUIT
Disconnect the Blend Door Actuator 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.
Istheresistancebelow10kohms?
Ye s>>
Repair the (C61) Blend Door Driver circuit for a short to the
(C34) Common Door Driver circuit.
Perform BODY VERIFICATION TEST – VER 1. (Refer to 8
- ELECTRICAL/ELECTRONIC CONTROL MODULES -
STANDARD PROCEDURE).
No>>
Replace the Blend Door Actuator in accordance with the
Service Information.
Perform BODY VERIFICATION TEST – VER 1. (Refer to 8
- ELECTRICAL/ELECTRONIC CONTROL MODULES -
STANDARD PROCEDURE).
5.RUN THE ACTUATOR DTC DETECTION TEST
Reconnect the A/C Heater Control C1 harness connector.
Turn the ignition on.
With the scan tool, erase HVAC DTCs.
With the scan tool, select System Tests and then select Actuator DTC Detection. When the test is complete, select
View DTCs.
Does the scan tool only display: B104D–BLEND DOOR CONTROL CIRCUIT LOW?
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 Blend Door Actuator via the (C61) Blend Door Driver circuit and the (C34) Com-
mon 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. 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 (C61) Blend Door Driver circuit is shorted to voltage.
Possible Causes
(C61) BLEND DOOR DRIVER CIRCUIT SHORTED TO VOLTAGE
A/C HEATER CONTROL
Diagnostic Test
1.CHECK (C61) BLEND DOOR 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 (C61) Blend Door Driver circuit.
Is the voltage above 0.2 volts?
Ye s>>
Repair the (C61) Blend Door 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: B104E–BLEND DOOR 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
Theory of Operation
The A/C Heater Control drives the Blend Door Actuator via the (C61) Blend Door Driver circuit and the (C34) Com-
mon 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. 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 Blend Door Actuator’s electrical circuit is open. This DTC has a maturingtimeof5secondsandade-ma-
turing time of 10 seconds. If the DTC’s status changes from active to storedit will stay in memory for 100
ignition cycles.
Possible Causes
(C61) BLEND DOOR DRIVER CIRCUIT OPEN
(C34) COMMON DOOR DRIVER CIRCUIT OPEN
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 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).
Theory of Operation
The A/C Heater Control drives the Recirculation Door Actuator via the (C32) Recirculation 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 share a single common door driver
circuit. 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 (C32) Recirculation Door Driver circuit is shorted to voltage.
Possible Causes
(C32) RECIRCULATION DOOR DRIVER CIRCUIT SHORTED TO VOLTAGE
A/C HEATER CONTROL
Diagnostic Test
1.CHECK (C32) RECIRCULATION DOOR 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 (C32) Recirculation Door Driver circuit.
Is the voltage above 0.2 volts?
Ye s>>
Repair the (C32) Recirculation Door 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: B105A–RECIRCULATION DOOR CONTROL CIRCUITHIGH?
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
Theory of Operation
The A/C Heater Control drives the Recirculation Door Actuator via the (C32) Recirculation 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 share a single common door driver
circuit. 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 (C32) Recirculation Door Driver circuit is shorted to voltage.
Possible Causes
(C32) RECIRCULATION DOOR DRIVER CIRCUIT SHORTED TO VOLTAGE
A/C HEATER CONTROL
Diagnostic Test
1.CHECK (C32) RECIRCULATION DOOR 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 (C32) Recirculation Door Driver circuit.
Is the voltage above 0.2 volts?
Ye s>>
Repair the (C32) Recirculation Door 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: B105A–RECIRCULATION DOOR CONTROL CIRCUITHIGH?
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
Theory of Operation
The A/C Heater Control drives the Recirculation Door Actuator via the (C32) Recirculation Door Driver circuit and
the (C34) Common Door Driver circuit. All of the door actuators share the (C34) Common Door Driver. Inside the
A/C Heater Control, each door actuator has its own unique driver, but all share a 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 ispresent.
When Monitored:
During actuator calibration.
Set Condition:
If Recirculation Door Actuator’s electrical circuit is open. This DTC hasa 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
(C32) RECIRCULATION DOOR DRIVER CIRCUIT OPEN
(C34) COMMON DOOR DRIVER CIRCUIT OPEN
RECIRCULATION 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 RECIRCULATION DOOR ACTUATOR CIRCUIT RESISTANCE
Turn the ignition off.
Disconnect the A/C Heater Control C1 harness connector.
Measure the resistance between the (C32) Recirculation 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).