Spn636, eng pos sensor timingsignal err (pcm343)

[Sport 200_2011]

I have a Nautique Sport 200 2011 with a PCM 343. (2011 with about 400h+)
It started by doing some ''misses'' lately..
I got a SPN 636 error (Eng Pos sensor timing signal Err)...
Mostly is happen at iddle or low speed.
Yesterday was a hot day and boat suddenly died, had serious trouble to start it. (would die right after starting)
By the sound of it, it is probably a bad sensor or wiring.. (cam shaft sensor).
I have seen post where the problem got cleared by replacing the throttle position sensor!!!
Would someone have seen this before? Ideas on where to start the diagnostic?
Don't know where to start without replacing various parts..
Thanks
Regards

[Sport 200_2011]

Just gave it a try today. When I disconnect the Throttle Control Position Sensor (R119005) the engine seems to be running just fine.
Of course, there is an alarm on the display, but the engine run smootly.
Has anyone experience a bad TCP Sensor? would it cause the engine to stop?
Just would like your opinion before ordering... the replacement is kind of pricy (@ $267.00 from Nautique Parts)..
Looking forward to your comments.... thanks

[Sport 200_2011]

Need advice, I have changed the Throttle position control sensor.. (had to get the ECM re-programmed)..
and still have a problem..
Mainly at idle... (and the boat cannot hold its rpm at around 1000rpm, it goes up and down)
My dealer has no clue how to help me.. (he has never seen a SPN636 code (Engine position timing signal error)...
I have verified the ''slack'' in the timing chain... I evaluated about 9degree.. so that seem within limit.... (and I have only 425 hours)..
Have anyone seen a bad ''crankshaft position sensor'' (R020038)?
Need ideas or tips to identify where to start the troubleshooting...
Thanks team... really looking for advice..

[Sport 200_2011]

For information, if this can help anyone.
I have replaced the Crankshaft position sensor and problem is solved..