2016 Nautique G21 Error Codes

[Wanderingheel]

Breaking the boat out of winterization and the boat threw the following codes - wondering if anyone had any experience in any of these, or should I break down and call the dealership?

DTC 1639 : PWM5 open or short to ground - CAM Phaser Control Circuit
DTC 1415: Exhaust Manifold Water Temerature (EMWT) 1 higher than expected stage 1
DTC 31: Oxygen (o2) sensor 1 heater open or short to ground
DTC 51: Oxygen (o2) sensor 2 Heater open or short to ground

Boat will turn over but not catch. Batteries were on trickle charger over the winter and show 12.0V. Charger shows both batteries are full.

2016 Nautique G21

[Walker1978]

I’ve got a 2018 G21 ZR4 in the UK.
Only had the boat a few months, used 5 times without any issues.
New batteries & was also on a trickle charger.
Tried to start, cranked but wouldn’t fire, after approx 5 seconds I got 3 out of the 4 faults you have, didn’t get 1415.
I then tried again & fired straight up, codes haven’t come back but would like to find out what caused it.
I assume it’s a wiring issue, not had chance to look yet, searched online for a wiring diagram to see if the 3 components go through the same connector or share the same earth etc but cannot find a diagram online.