This 2002 Toyota Highlander with automatic temperature controls came in with the complaint that the air conditioning controls head was stuck at 84°F in the middle of summer. The setting would not change regardless of control movement. The system was putting out hot air also.
The trim panel around the HVAC control panel is secured with plastic spring tab clips. I used a plastic pry bar at the location below to work the panel loose.
Then proceeded to do the same around the rest of the panel.
A view of the plastic retainers.
There are multiple screws around the outside edges of the HVAC control head assembly and the radio that have to be removed.
One kind of test that I discovered was that if the harnesses are disconnected from the HVAC control head and then reconnected after a slight wait time…..
…..the panel would reset to 75°F. The vent temperatures also adjusted to the cooler setting. This along with some research into the issue confirmed my suspicion that there is an internal problem in the HVAC control head.
The control head and the radio need to be separated at this point. I removed the two upper screws shown below as well as their counterparts on the opposite side.
I then flexed the bracket enough to separate the two components.
Not exactly sure why I took this picture but it does show that the two parts can be separated after the attaching screws have been removed.
I found a vendor that would repair the HVAC control assembly and shipped it off. They also offered an exchange unit but the cost was obviously higher. My customer was more than willing to wait a few extra days to get his Highlander back in order to save $150 USD. When it returned everything worked as it should. We were very happy with the repair service.