Alarms- multiple alarms

[artdf175]

I think I may have discovered the cause of the engine throwing multiple alarms.
I now believe the engine interface cable to be the culprit.

history: Batteries charged. I would be running from one place to another and suddenly several alarms were popping up one after another. Over heat - over Rev'ing - low voltage. Then along with the over Rev'ing- the engine would go from 5,000 rpm to 4,000 and be stuck there.. could run it lower but would not run over that. Turn off the engine (reset the ECU) and restart it and shortly it would repeat the error alarm(s).
I took the wiring apart several times looking for bad connections, finding none. All the sensors check out being ok.
watching the engine info on the plotter screen noticed the RPM gauge jumping from off the meter to zero to off the top.
Then several weeks ago disconnected the interface cable and seemed to run fine. took the boat down to a launch ramp so to run at a higher RPM and engage the prop and worked fine.
Final test - take the boat fishing and be able run for a good period of time and distance.
That happened last Friday. No more errors. engine not cutting back to 4,000 RPM. just ran perfect all day.
And, by the way, I found nothing that explains why it would cut back to 4,000 RPM... 3,000 is the only level the manual talks about.
Hopefully this info may help someone else.
Art

[Murray]

Thanks Art. Wonder how many people we gave advice to about a low voltage/bad battery when in fact it could have been a bum engine interface cable?

[Moonlighter]

There have been a number of cases now where failing interface cables were the root cause of the multiple false alarms/codes.

For some time now I have been mentioning that as a possible cause in my replies to members on this forum and others.

It is still the case however that the most common cause is voltage supply to the ecu, caused by bad batteries, corroded wiring/plugs/white wire.

Its interesting to understand what is going on there.

What we DO know is that the interface gets the power it needs to operate from its connection to the SDS plug, which of course comes directly from the ecu.

It stands to reason then, that if the ecu is not getting the required power to operate properly, then that is going to have a direct flow on effect for the interface. Causing it to throw false codes and potentially get into a feedback loop with the ecu, which can then cause engine running issues. A viscous circle.

I’ve been talking to Art about his problem for a while via messenger and thats what eventually lead to disconnecting the interface.

He is going to try a test that involves providing a separate power source to the interface (not from the engine/ecu) to see if that makes any difference just in case there is something strange going on with the ecu’s power wire providing good power to the interface. This will either confirm a failing interface cable, or point the finger at the ecu or the wiring from ecu to the SDS plug. We shall see the results when he gets time to do that.