Afternoon all

, just wondering if anybody knows where i can get a part for something.
During all the snow in november, december time i slid into the back of somebody at about 5mph, no damage was done but the engine management light came up on my dash.
Took the car to my mate so he could plug it into the computer and its because of the outside air temperature control switch or something. Basically all it is, i now cant see the outside temperature, all i get is -- C

.
Wondering if anybody has had a similar fault and had it fixed... need to know where to get the part for it.
any help would be appreciated