The trip computer doesn't appear to be working correctly on my A3. The MPG jumps around wildly, the average speed is stuck at 21mph, the average MPG is stuck at 37.8MPG and, the total driving time doesn't reset. Any thoughts on what the problem might be?

 

The 'wild jumps' in (instantaneous) MPG are totally normal, unless all your driving is by cruise control on a flat road.

The other symptoms don't sound right, however. Have you tried resetting them?

Trip Computer 1 should auto-reset whenever the car has been turned off for more then 2 hours. Does that work properly?

 

Thanks for the reply DF. Trip computer 1 is not resetting automatically, total driving time at 70hrs+. As for trying to reset it manually, I've not tried that yet, will have a look in the owners manual to find out how to do that. I'm assuming the reset procedure for an A3 will be the same as the A4 Avant, didn't get owners manual with the A3 but, my girlfriend has one in her A4.

 

There is a button on the bottom of the trip wand that you use to switch between trip 1 and trip 2. Depress it for 2 seconds and whatever information is being displayed will reset. This works for Distance, Avg. MPG, Avg. Speed, and Time. However you should only need to use this on Trip 2. DF stated correctly that trip 1 "should" reset automatically after the car sits for 2 hours off.