Temp on Mirror Reads Wrong

I recently hit a deer and after getting my 2003 Tahoe back from the body shop, the temp gauge on the mirror always reads about 10 degrees warmer than the actual temp...what is causing this / how can I fix it?

The temp sensor or sending unit I believe is located near the front bumper and may have been damaged.

Thank you, think I will take it back to the body shop and see if they can get the insurance to cover it...would think it would be from the crash since it worked fine before that...???

Thank you 777Stickman...That is exactly what is was! Took it back to the body shop and they replaced the $2 part in a matter of minutes and I was on my way...