Here's the scenario. 2001 Audi A4 with a little over 90K.

Driving around town the temperature reading is constant thus allowing the climate control to function normally. But when I drive on the highway or drive for extended periods of time the temperature will begin to give crazy readings like -40 degrees (not possible for a Carolina summer). This temp. reading won't allow me to turn on the A/C. Is there a way to over ride this?

I have replaced the temp sensor on the bumper and am still having the problem. What gives?

Thanks.

ect sensor?

doesn't that only have to do with the actual engine temp? not sure if that would help...

check the wires that run out to that sensor behind the bumper.. there may be a short somewhere along the way, and check the connectors make sure they are clean. I say this because mine was kind of doing this. somehow wire came loose and got cut in two right under the bumper by dragging through a gutter or something and it was still giving readings, but it was way off, like it said it was zero degrees and it was warm outside.. just my guess

I think there is two temp. sensors....I have the same problem. It hasn't really happened lately and when it does happen it doesn't last that long. Do a search on air temp. sensors and you should get something.