rearview mirror outside temp is wrong

Does anyone know of a way you can reset the outside temperature feature on the rearview mirror or a way to fix it. It is completely wrong and sometimes it displays "SC". I don't even know what that means. Any comments would be truly appreciated

"SC" means system check, and something is out of specs. The test procedure is quite involved for diagnosing the system. It involves checking resistance values and connections from the ambient sensor, (behind the grille near the hood latch) to the DIC (Driver Information Center). You might check the connections at the ambient sensor, if that doesn't fix it, try replacing it.