Is there any way, other than holding the relevant button, that the trip computer can get reset?

I was driving along last night and it must have reset itself mid-journey. Unless it only has a 3 month memory?

100 hours or 10k miles make it do that on 2 (the long term trip computer). TC1 resets after 2 hours IIRC.

What Jon said Plus disconnecting the battery can do that too, although that's slightly harder to do while you're driving along

Chris

Pretty certain I didn't manage to disconnect the battery LOL

Must have been 100 hours - that would fit with about 4000 miles I guess...

2 hours seems right for the "1" setting too.

The trip counter under the odometer resets itself after 2000 miles on mine. I think the one in the trip computer display does too. It's supposed to according to the manual, but it ain't half a nuisance