Orange Light Issue!

Hi Guys

My 2002 1.8T 4X4 hatch has been serviced 3k miles ago and is running sweetly other than a tiny misfire when first started. This is a tiny blip under light throttle and has been doing it for approx 6k miles.

The car isnt running rough, tappetty, burning oil, using too much fuel etc......

However, friday eve I was driving home and all was well. Stopped at the shop for 30mins and then restarted to see the engine management orange light on :eek: !!

The only thing that I did that was unusual was I turned on the air con (usually have it on ECON mode)

Could this be linked?

Any ideas? Should I panic or not quite......?

Obviously read some of the more pertinent post suggesting 'flighty' ECU faults.

Appreciate all your help and advice guys