2007 Grand Cherokee WK Factory Service Manual 24 - HEATING & AIR CONDITIONING

54-REAR MODE DOOR LINKAGE BROKEN (MTC)

For a complete wiring diagram Refer to Section 8W.

Theory of Operation


NOTE: Diagnose and repair Actuator Circuit Test faults (DTC 61, 62, 63, 64, 65, 66, 67, 68, 69, 71, and 72) before diagnosing Overcurrent faults (DTC 41, 42, 43, and 44) and Calibration faults (DTC 18, 21, 22, 23, 24, 25, 45, 46, 47, 48, 51, 52, 53, 54, 55, and 56). Diagnose and repair Overcurrent faults (DTC 41, 42, 43, and 44) before diagnosing Calibration faults (DTC 18, 21, 22, 23, 24, 25, 45, 46, 47, 48, 51, 52, 53, 54, 55, and 56).

The purpose 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 A/C Heater Control detects and excessive amount of commutator pulses when calibrating the rear mode door, this DTC will set.



Possible Causes
 
ACTUATOR CIRCUIT TEST FAULTS PRESENT
 
OVERCURRENT FAULTS PRESENT
 
REAR MODE DOOR OR A/C HEATER HOUSING COMPONENTS DISCONNECTED, MISSING, BROKEN
 
REAR MODE DOOR ACTUATOR
 
A/C HEATER CONTROL
 




Diagnostic Test

1. VERIFY IF ANY ACTUATOR CIRCUIT TEST FAULTS OR OVERCURRENT FAULTS ARE PRESENT

Turn the ignition on.
Actuate the Clear DTC function by performing the following:
Turn the ignition off, wait 10 seconds, and turn the ignition on.
Actuate the Actuator Circuit Test / Door Calibration Function by performing the following:
Actuate the Display DTC function by performing the following:

NOTE: The A/C status indicator displays active DTCs when the EBL status indicator is not illuminated and stored DTCs when the EBL status indicator is illuminated.


Read DTCs from the A/C status indicator.

Does the A/C status indicator display any of the following DTCs: 41, 42, 43, 44, 61, 62, 63, 64, 65, 66, 67, 68, 69, 71, or 72?

Yes


No

2. CHECK FOR A BROKEN REAR MODE DOOR ACTUATOR

Turn the ignition off.
Remove the Rear Mode 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


No

3. CHECK THE REAR MODE DOOR & A/C HEATER HOUSING FOR DISCONNECTED, MISSING, & BROKEN COMPONENTS

Inspect for disconnected, missing, or broken door linkage. Inspect for a damaged or broken A/C Heater Housing Assembly and a broken door. Rotate the door from stop to stop. The door should rotate approximately 155 degrees.

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

Yes


No

4. VERIFY IF THE FAULT IS STILL PRESENT

Turn the ignition on.
Actuate the Clear DTC function by performing the following:
Turn the ignition off, wait 10 seconds, and turn the ignition on.
Actuate the Actuator Circuit Test / Door Calibration Function by performing the following:
Actuate the Display DTC function by performing the following:

NOTE: The A/C status indicator displays active DTCs when the EBL status indicator is not illuminated and stored DTCs when the EBL status indicator is illuminated.


Read DTCs from the A/C status indicator.

Does the A/C status indicator display DTC 54?

Yes


No