Rear View Mirror Help!!

I need to know why the outside temp does not work and the compass does in my 2002 silverado, I just got it and it does work but my truck did not come with it from the factory, and I'm wondering also if anyone knows where the temperature sensor may be and if my truck may need one or does the ecm have to be flashed.

If your truck did not come with one, then it does not have the temp sensor attached to it. There is a post on here with the same problem you had and there were several solutions. Do a search on compass

Here is a post that may answer your question
http://www.automotiveforums.com/vbulletin/showthread.php?t=646235&highlight=compass

Yeah It does tremendously, Thanks And Nice Silverado