Service Engine, CHECK and MIL lit up, boat stops working, intermittently

[NachoDad]

Hi All, new Axis A20 2018 owner, love it, bought it used and really love the time boating, no place better during isolation.

New problem last Sunday, SERVICE ENGINE error with CHECK and MIL lights lit up. I went into codes and see: 

Fault 1, SPN 91 FMI 16

Fault 2, SPN 91, FMI 18

I looked this up and both ahve to do with FPP --- FPP1 Lower than FPP2 and the other is FPP1 Higher than FPP2

I called my dealer, they're closed today, hope to speak to someone tomorrow, but I wonder if anyone has seen this and has an idea of a loose cable or what FPP cables are?

I did clean the battery terminals and reattach. Boat worked for 20 min then had that problem, the boat only works at 0-1 MPH after the error. I have to shut it off, turn off the battery, then back on, then it works for 30 seconds before coming back with that error. So its basically unusable in its current state. 

The compartment under the steering wheel somehow was loose and I wonder if a cable came loose or if someone could point me in the right direction. 

Otherwise will deal with dealer.... Thank you! Carl

 

[csleaver]

Those codes are for the Throttle Control Position (TCP) sensors.  They are integrated into the throttle body electric motor control on the engine.  You will usually get this alarm if there is a loose connection or corrosion on the plug connection, low voltage, a poor engine ground, internal failure in the throttle control motor, or an issue with the wiring harness.  A problem with the helm throttle/shifter or connections could also cause this alarm.  When it happens, the MIL and audible alarm will turn on, a power derate, low rev limit, or forced idle speed will occur.

You should be able to check the battery condition and connections, engine compartment power post, starter and ground cable connections, and the TCP harness plug to see if something is loose.  Anything beyond that should be handled by your dealer.