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Dodge Durango (HB). Manual - part 1506

B1050–BLEND DOOR TRAVEL RANGE TOO SMALL (ATC & MTC)

For a complete wiring diagram Refer to Section 8W.

•

When Monitored:
During actuator calibration.

•

Set Condition:
If the total span of the Front Blend Door is less than the low range limit.

Possible Causes

DOOR DRIVER ELECTRICAL CIRCUIT(S)

FRONT BLEND DOOR SEIZED, BINDING, OBSTRUCTED

FRONT BLEND DOOR ACTUATOR

A/C HEATER CONTROL

Theory of Operation

The A/C Heater Control calibrates each actuator individually. Automatic calibration occurs upon power up after
installing a new A/C Heater Control. Manual calibration occurs by sending a 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 its soft 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 that the control clears all
stored calibration faults at the beginning of the calibration procedure.

Diagnostic Test

CHECK FOR ACTIVE CONTROL CIRCUIT/PERFORMANCE & CONTROL CIRCUIT OPEN DTCs

Turn the ignition on.

With the scan tool, read active HVAC DTCs.

Does the scan tool display any active: XXXX CONTROL CIRCUIT/PERFORMANCE or XXXX CONTROL CIR-
CUIT OPEN DTCs?

Yes (ATC)

Diagnose and repair the DTC(s). If present, diagnose and repair all Rear Blend and Rear Mode Door
Control Circuit/Performance DTCs first, all other Control Circuit/Performance DTCs second, and all Con-
trol Circuit Open DTCs last. Refer to the Table of Contents in this Section for a complete list of all HVAC
related symptoms.

Yes (MTC)

Diagnose and repair the DTC(s). Refer to the Table of Contents in this Section for a complete list of all
HVAC related symptoms.

>> Go To 2

RUN THE ACTUATOR DTC DETECTION TEST

With the scan tool in HVAC, select System Tests and then select Actuator DTC Detection. When the test is com-
plete, select View DTCs.

Does the scan tool display any DTCs?

Yes

>> Diagnose and repair the DTC(s). If multiple DTCs are present, beginning with the common circuits, diag-

nose and repair all short high DTCs first, all short low DTCs second, and all open DTCs last. Refer to
the Table of Contents in this Section for a complete list of all HVAC related symptoms.

>> Go To 3

HVAC - ELECTRICAL DIAGNOSTICS

24 - 217

B1050–BLEND DOOR TRAVEL RANGE TOO SMALL (ATC & MTC) (CONTINUED)

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?

Yes

>> Repair as necessary in accordance with the Service Information.

Perform BODY VERIFICATION TEST - VER 1.

>> Go To 4

CHECK FRONT BLEND DOOR TRAVEL

Remove the Front 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 65 degrees of travel.

Does the door operate smoothly in both directions over approximately 65 degrees of travel?

Yes

>> Replace the Front Blend Door Actuator in accordance with the Service Information. Then, Go To 5.

>> Repair as necessary in accordance with the Service Information.

Perform BODY VERIFICATION TEST - VER 1.

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: B1050–BLEND DOOR TRAVEL RANGE TOO SMALL?

Yes

>> Replace the A/C Heater Control in accordance with the Service Information.

Perform BODY VERIFICATION TEST - VER 1.

>> Perform BODY VERIFICATION TEST - VER 1.

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HVAC - ELECTRICAL DIAGNOSTICS

B1051–BLEND DOOR TRAVEL RANGE TOO LARGE (ATC & MTC)

For a complete wiring diagram Refer to Section 8W.

•

When Monitored:
During actuator calibration.

•

Set Condition:
If the total span of the Front Blend Door exceeds the high range limit.

Possible Causes

DOOR DRIVER ELECTRICAL CIRCUIT(S)

FRONT BLEND DOOR OR A/C HEATER HOUSING COMPONENTS WARPED, WORN, DAMAGED, MISSING,
BROKEN

FRONT BLEND DOOR ACTUATOR

A/C HEATER CONTROL

Theory of Operation

The A/C Heater Control calibrates each actuator individually. Automatic calibration occurs upon power up after
installing a new A/C Heater Control. Manual calibration occurs by sending a 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 its soft 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.

Diagnostic Test

CHECK FOR ACTIVE CONTROL CIRCUIT/PERFORMANCE & CONTROL CIRCUIT OPEN DTCs

Turn the ignition on.

With the scan tool, read active HVAC DTCs.

Does the scan tool display any active: XXXX CONTROL CIRCUIT/PERFORMANCE or XXXX CONTROL CIR-
CUIT OPEN DTCs?

Yes (ATC)

Yes (MTC)

Diagnose and repair the DTC(s). Refer to the Table of Contents in this Section for a complete list of all
HVAC related symptoms.

>> Go To 2

RUN THE ACTUATOR DTC DETECTION TEST

With the scan tool in HVAC, select System Tests and then select Actuator DTC Detection. When the test is com-
plete, select View DTCs.

Does the scan tool display any DTCs?

Yes

>> Diagnose and repair the DTC(s). If multiple DTCs are present, beginning with the common circuits, diag-

nose and repair all short high DTCs first, all short low DTCs second, and all open DTCs last. Refer to
the Table of Contents in this Section for a complete list of all HVAC related symptoms.

>> Go To 3

HVAC - ELECTRICAL DIAGNOSTICS

24 - 219

B1051–BLEND DOOR TRAVEL RANGE TOO LARGE (ATC & MTC) (CONTINUED)

CHECK FOR A BROKEN FRONT BLEND DOOR ACTUATOR

Turn the ignition off.

Remove the Front 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?

Yes

>> Replace the Front Blend Door Actuator in accordance with the Service Information.

Perform BODY VERIFICATION TEST - VER 1.

>> Go To 4

CHECK FRONT 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 65 degrees.

Are there any physical or mechanical problems with the door or housing?

Yes

>> Repair as necessary in accordance with the Service Information.

Perform BODY VERIFICATION TEST - VER 1.

>> Replace the Front Blend Door Actuator in accordance with the Service Information. Then, Go To 5.

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: B1051–BLEND DOOR TRAVEL RANGE TOO LARGE?

Yes

>> Replace the A/C Heater Control in accordance with the Service Information.

Perform BODY VERIFICATION TEST - VER 1.

>> Perform BODY VERIFICATION TEST - VER 1.

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HVAC - ELECTRICAL DIAGNOSTICS

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