The mk3 has a design flaw that means the ABS loom and the crank sensor and coil share a bundle of cables. In damp weather this produces interference. I've been looking for the notice online that detailed it - if i find it i'll post it here. In a nutshell - let it dry out and clear the code. You can separate the looms and tie one to the side (against strut housing) but it's a lot of effort - I never bothered.