Diagnostic Test

WARNING: This page is about a different car, the 2005 Jeep Grand Cherokee. However, it is still accessible from the selected car via links, so may be relevant.

1) 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 CIRCUIT OPEN DTCs?

Yes
1. Diagnose and repair the DTC(s). Refer to the DIAGNOSTIC CODE INDEX for a complete list of all HVAC related symptoms.
No
1. Go To step 2).
2) RUN THE ACTUATOR DTC DETECTION TEST
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 display any DTCs?

Yes
1. Diagnose and repair the DTC(s). If multiple DTCs are present, diagnose and repair all short high DTCs and then all short low DTCs. Refer to the DIAGNOSTIC CODE INDEX for a complete list of all HVAC related symptoms.
No
1. Go To step 3).
3) RUN ACTUATOR CALIBRATION TEST
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 any DTCs?

Yes
1. Diagnose and repair the DTC(s). Refer to the DIAGNOSTIC CODE INDEX for a complete list of all HVAC related symptoms.
No
1. Go To step 4).
4) CHECK MODE, BLEND & RECIRCULATION DOOR OPERATION
Start the engine.

Set the blower to high speed.

Operate each door in all positions in one direction and then in the opposite direction while monitoring the following:
1. For the Mode Doors, verify that air flows from each vent accordingly for the position selected on the A/C Heater Control.
1. For the Blend Door, verify that the airflow air temperature changes accordingly for the temperature range selected on the A/C Heater Control.
1. For the Recirculation Door, verify that the sound of the air flow get louder as the recirculation door opens to bring in recirculated air or gets softer as the recirculation door closes to bring in fresh air.
Does each door operate properly?

Yes
1. The condition causing the fault has cleared at this time.
2. Perform BODY VERIFICATION TEST - VER 1 .
No
1. Remove the door actuator of the affected door from the A/C Heater Housing Assembly. By hand, attempt to rotate the actuator in both directions. Inspect the A/C Heater Housing for damage, for disconnected, missing, or broken linkage, and for broken or binding doors. Repair as necessary in accordance with the Service Information.
2. Perform BODY VERIFICATION TEST - VER 1 .