Wagz won't spin past 4000 rpm?

[6LWAGON]

I took the girl in for a laser (lazy) wash the other day and went for a bit of a squirt.
Going through the gears it was like the rev limiter had been changed to 4000rpm which isn't good.
Only happened for about 10 minutes and then everything was ok. No engine lights came or anything else.
I have a VCM OTR and maybe water might have affected it.Any thoughts on the cause would be great.

[HoldenCommodoreVE]

Best guess would be that water played up on the electronics, water in a sensor plug or something like that

[TinSnips]

Need to be (a bit) careful with water around an OTR. I generally bag them just to be on the safe side - normally no issue unless a water jet is angled directly into it though. Check your filter to see if you can see any evidence of this. Other than that, not sure.