[hulvhole]

Having an issue with the AC on a 2003 Envoy. The HVAC control unit randomly shows different outside temps, only some of which are remotely correct. I have performed the three button calibration numerous times to get the problem to go away without luck. Now, the real confusing problem. When the exterior temp is displaying lower than true temp (32 degrees on a 75 degree day for example) the AC will not kick on. Once the outside temp starts to display normal temps the AC begin to work.

Has anyone had similar issues? Do you think it is the outside temp sensor or a need to reprogram the HVAC controls? Any input would be appreciated. The outside sensor seems easy to replace but I do not want to go that route if it will not fix the problem. Thanks.

 

[cbwilsha]

It is the Ambient Temperature Sensor needing replacement. Cheap and easy. It is a common problem. If you have problems finding or replacing it, run a Search above for "Ambient Temperature Sensor" and you will find directions including pictures.

C.B.

 

[docdrs]

i have this same problem, replaced the sensor and no change, there is leak at one of the ac connections at the front passenger side so i will address this and see if maybe its a pressure issue inside the ac

 

[docdrs]

replaced the sensor, fixed the ac leak but the reading on the display still fluctuates........it will read the correct temperature then spiral downward at random times then back up to the correct temp 5 or 10 mins later.........anyone have anyideas?
:bonk:

 

[the roadie]

Some open or intermittent wire in the harness going to the sensor. Are you up for tracing it all the way back to the HVAC control module connectors inthe dash?