X-2 SS Check Engine Light

New to the Mastercraft family and having some issues with a check engine light. I have a 2006 X-2 SS with a Crusader 5.7 with a Hurth transmission. I have read the fault code and it is DTC 81.

I have checked the raw water impeller and it looks new, there was a lot of debris in the raw water strainer, but I cleaned that out and I am still getting the check engine light after I clear the code. The raw water pump seems to be running well, it's pulling about the same velocity as a garden hose.

Can someone please point me in the right direction, the nearest mastercraft shop is 2.5 hours away.

Thanks.