Golf ECP light ... most common causes

[lpresson]

What are the most common causes of this light coming on?
I have a 2001 1.8 l turbo , has been a perfect car until last week.
VW dealer says they can't find anything, but the light is still on and the engine dies sometimes.

It has been well maintained, oil. tune-ups etc. Looks and drives like a new car, but..... the ECP and sometimes the check engine light comes on.

Need help.