i've tried this below advice, and so far in various combos of turning the key and pushing/turning the buttons all i've managed to do is reset miles, change temp to Fahrenheit, enter the diagnostics mode and finally the settings screen, which doesn't include temp adjustment

mines around 4c too high i reckon, not sure when this happened as it used to be fairly accurate with weather reports and my own temp sensor in the house.

You can adjust it + and - 3 degrees. Its a similar procedure to resetting the amber maintenance light. Instead of pushing both SELECT and RESET buttons before you turn the key on (to reset the light), turn the key on and then push and hold both bottons. You can then manipulate the temp display plus and minus 3 degrees.

Cheers, Phil.

Mine cannot be reset, only changed from fahrenheit to centigrade , perhaps yours is the same and the displayed temp is correct

nope,it's deffo wrong, sensor on the side of the house shows 1.8c, car thinks it's 6. the other night it was 0 by all accounts, car showed 4.

several cold mornings recently its showed 4-6 c while others come in 4c lower, it's a little annoying, but knowing when the temps dropped is an important feature, as there's several ice spots on my drive into work.