That sounds like a defective mode door actuator. It adjusts the airflow from defrost to dash to floor. Testing it on that vehicle requires a scan tool that can communicate with the HVAC system. That way you can tell if the fault is in the control head or in the actuator itself. With the scan tool you can adjust the door to defrost, then watch as the HVAC unit tries to adjust the actuator. If the control head was set to defrost but it never sends out the signal to the mode door, then it's likely a bad HVAC controller. That is right in the dash. If, however, it does send it but there is no change in the actuator's position, then it's the actuator or the wiring to it. It is also possible that it's a broken mode door as well. Replacement of the HVAC control head and the actuator both require a scan tool to initialize them through the PMI process.
Replacement of the control head.
Removal steps in this procedure may contain installation details.
If installing a new module, it is necessary to upload the module configuration information to the scan tool prior to removing the module. This information must be downloaded into the new module after installation.
Using a diagnostic scan tool, begin the PMI process for the HVAC control module following the on-screen instructions.
Remove the Audio Front Control Module (ACM) (this is the entertainment and display in the center of the dash.
Remove the bolt and the HVAC control module. Disconnect the electrical connectors. Reverse to install the replacement and finish the PMI process with the scan tool.
Replacement of the actuator though requires removal of the brake pedal and bracket and then removal of the instrument cluster in order to access the actuator on top of the HVAC housing.
This is a pretty good video on the actuator replacement:
https://www.youtube.com/watch?v=LIDLq4jLZXE
Images (Click to make bigger)
SPONSORED LINKS
Wednesday, August 30th, 2023 AT 1:24 PM
