A 2015 or newer FX SVHO or Cruiser SVHO throws error 159, the reverse gate won't move, and the first reaction is to blame the control unit. Owners who have been through this describe something less dramatic. The reverse gate sits at the back of the boat, gets knocked about, and the cause turns out to be mechanical or a plug far more often than a dead module.
Which boats this applies to
RiDE is the system with the SCU control unit and the RPS position sensor. On the FX SHO and SVHO it arrived in 2015, so the 2012 to 2014 boats still use a plain reverse switch (code 78) and don't have this problem at all. The same SCU and RPS arrangement is found on the GP1800 and GP1800R, on the RiDE trims of the VX, EX and JetBlaster, and on the 1.9 litre boats. An FX HO 1.8 from 2008 to 2014 has no RiDE.
Code 159 falls into the SCU range of 157 to 164, and the RPS codes run from 150 to 154. Numbers differ between control unit generations and between sources, so go by the description the app shows rather than by a number copied from a thread.
The dull causes, in the order I would work through them
- A tie-down strap pulled across between the two rear eyes. It can sit right in the way of the gate. Take it off first.
- Something stuck at the gate itself, a stone, rope or weed. Look before you touch anything electrical.
- The rod. A slightly bent one is enough to upset the gate, and it can look straight at a glance.
- The connector on the RiDE main harness. Unplug it, check that it is dry and clean, and push it back until it seats fully.
- The relay and the fuse belonging to the system.
- The cable adjustment of the gate mechanism, if the gate has ever been moved or worked on.
All of this can be done at the trailer, and most of it costs nothing but time.
Clearing the code and watching whether it returns
With the fault stored, you can clear it by hand: engine off, lanyard pulled, wait 30 seconds, start again. Then run the gate once. If 159 comes straight back, it is active and the circuit really is complaining right now. If the boat reverses normally and the code stays away, you most likely fixed or moved whatever was causing it. The app can clear the memory as well, and clearing the fault memory is worth doing only after you have written down what was in it.
What the scan shows and where it stops
The M-JET Diagnostic reads the SCU and RPS codes on every supported RiDE model and gives the likely cause and test steps for the code in plain language. That tells you which circuit objected. It does not tell you why. A bent rod, a wedged gate or a plug that looks fine and still makes poor contact leaves no extra mark in the data, so the mechanical inspection above stays your job.
The app also has an SCU initial learning routine for RiDE models. I would not treat it as the next step after a strap or a bent rod, because learning does not repair anything mechanical. It matters more once the control unit itself or the related parts have been replaced.
If 159 keeps coming back after all of that, you have at least eliminated the cheap causes and know what to describe to whoever looks at the wiring next. The SCU initial learning page explains what the learning routine does and when it applies.
