GMC Repair: Outside temp gauge, radiator support, gmc envoy

Question
The good news is it doesn't read 50 degrees anymore.  The bad news, it reads -39.  Does this mean I need to go to the dealership?

Thanks,
Dylan

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Followup To
Question -
Most of the time my 2002 GMC Envoy's outsied temp gauge says 50 degrees.  It is built into the Electronic tempature control.  Is there anything I can install that will fix this?
Answer -
Hi,Dylan

 This has been a common problem with the Envoys,one thing you can do is reset the ambient temp to current,to do this on your HVAC panel simultaneously press the MODE,FT DEFROST,and REAR DEFROST buttons,the display should change to current Ambient temp,monitor the temp,if it still defaults to 50 deg,then the HVAC module would need to be programed to a new calibration,this can only be done at the dealership.

ED

Answer
Dylan

Ok good we know the HVAC module is responding and not failed,look for the ambient temp sensor,it is located behind the grill and mounted to the radiator support,looks like a small gray square box,has 2 wires at the connector,you may need to remove the ft grill to access it,check to see that its plugged in and that the wires to it are ok,unplug it and look at the terminals,make sure they are good and not bent back or pulled out,if all is good there then its possibly the ambient temp sensor and needs to be replaced,after you check the ambient temp sensor,do the recal update prcedure that ive told you before and see if it shows true temp,if its still the same,replace the sensor.


ED