Difficult to say, as there are a lot of parts involved to get an anti-skid-message... If you can get your hands on a code reader, it would be much easier to pinpoint.
What you can do without a reader:
- check the reluctor rings / abs sensors for dirt or debris that came with the water (maybe a good clean helps here).
- check the cables going to these sensors. Are they ok?
- check the BCM (brake control module), especially the big plug, for water ingress.
As I said, a readout would help a lot, as it would narrow the possibilities down to one or two wheels, so you could investigate further.
Note: if you get an anti-skid-message there are numerous things that won't work! ABS, DSTC and basically all electronic assistants, that have to do with road grip! That means you should drive carefully, your brake power, as well as your grip, will be reduced and is not supported by any electronic helper!
Just keep that in mind and don't push it.
