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

47-RECIRC DOOR BOUND (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 no commutator pulses when calibrating the recirculation door, this DTC will set.



Possible Causes
 
ACTUATOR CIRCUIT TEST FAULTS PRESENT
 
OVERCURRENT FAULTS PRESENT
 
(C268) RECIRCULATION DOOR DRIVER CIRCUIT OPEN
 
(C68) RECIRCULATION DOOR COMMON DRIVER CIRCUIT OPEN
 
RECIRCULATION DOOR SEIZED, OBSTRUCTED
 
RECIRCULATION 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 THE RECIRCULATION DOOR ACTUATOR CIRCUIT RESISTANCE



Turn the ignition off.
Disconnect the A/C Heater Control C2 harness connector.
Measure the resistance between the (C268) Recirculation Door Driver circuit and the (C68) Recirculation Door Common Driver circuit in the A/C Heater Control C2 harness connector.

Is the resistance above 70.0 ohms?

Yes


No

3. CHECK THE (C268) RECIRCULATION DOOR DRIVER CIRCUIT FOR AN OPEN



Disconnect the Recirculation Door Actuator harness connector.
Measure the resistance of the (C268) Recirculation Door Driver circuit between the A/C Heater Control C2 harness connector and the Recirculation Door Actuator harness connector.

Is the resistance below 5.0 ohms?

Yes


No

4. CHECK THE (C68) RECIRCULATION DOOR COMMON DRIVER CIRCUIT FOR AN OPEN



Measure the resistance of the (C68) Recirculation Door Common Driver Circuit between the A/C Heater Control C2 harness connector and the Recirculation Door Actuator harness connector.

Is the resistance below 5.0 ohms?

Yes


No

5. INSPECT ACTUATOR & HOUSING ASSEMBLY FOR A CONDITION CAUSING THE RECIRCULATION DOOR TO SEIZE

Turn the ignition off.
Inspect the actuator, linkage, and housing assembly for a condition causing the recirculation door to seize.

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

Yes


No

6. CHECK RECIRCULATION DOOR TRAVEL

Remove the Recirculation 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 the entire span of travel (approximately 85 degrees).

Does the door operate smoothly in both directions over the entire span of travel?

Yes


No

7. 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 47?

Yes


No