I have the same boat. 90% of the time its' the water pressure sensor. The average life is about 2 years. I've replaced mine multiple times . They are pricey but recently I saw them being sold for a 1/3 the price with pretty good reviews. Chinese of course. Check your port smart craft gauge by scrolling until you get to water pressure. The number should be something like 3 to 5. when the number is up around 40 it needs replacement (I'm doing the numbers from memory so I could be off a bit). There's also another sensor that goes bad but nearly as often. The part is in my bag on the boat so I can't recall its exact name but it looks a lot like the water pressure sensor. If you need more assistance, feel free to contact me.