Ambient sensor-A/C 02 TB

[fletchoman]

My 02 TB sometimes shows an incorrect outside temperature (center console). I have purchased a new ambient air sensor from GM but replacing the sensor did not correct the problem. I also tried removing the sensor completely and shorting the 2 sensor wires, but the reading (50*F) never changed. Does the computer use ambient temperature to determine when/if to engage the fan clutch when the A/C is turned on?

I have an OBDII diagnostic setup (Mobydic). Is there a way to determine where the problem is through OBDII? I am trying to solve an air-conditioner problem; when outside temperature is hot, air conditioner does not cool effectively at idle (suspect fan clutch). Is it possible to test system to determine if the computer is at fault?

[Twin1]

I had the same problem on my 02 TB, i didn't have to change the sensor , i read on a post a while back all you had to do was press 3 of the buttons on the a/c panel at the same time and it reset it and worked for me . the only problem is I don't remember what 3. Check out this forum a few months back, because that when i saw it and it worked fine for me.

[Twin1]

I found the thread for you. It was started on 3/5/07 "AC Thermostat External sensor. Some people changed the sensor it's behind the front grill or try what i did press the mode,defrost, and rear defrost at the same time.

[ladybug1348]

I have a 2002 TB and the A/C was doing the same thing. I suspected it had something to do with the sensor since when it was not cooling well, the external temp read 50. Once it quit altogether and the temp read 24. I tried the 3-button reset but it went to -139. I replaced the ambient air temp sensor and it now works great. Thanks for the info. I spent $20 on the part and probably saved several hundred dollars at the dealer!