Check Engine Lights--Both Engines--No Apparent Issues

[JDRacing]

So, I hadn't had my boat on the lake this season for a variety of reasons, but finally got the chance over Labor Day with the extended family. After warm up, it started missing on both engines a bit and I got check engine lights/alarms for both engines, but other than that, everything was normal--pissers, etc, and no other warnings beyond the check engine lights.

Boat has 31 hours on it (I know, I love this boat but life often gets in the way of boating). Anyway, after the engines cleared out, the lights stayed on, but the thing ran great. Had 6 people on it, 4 of whom insisted on riding in the bow, and was still pulling 7500-7600 RPM at 45-46 mph. With two of us, it's usually 48 mph and on a cool day by myself I've hit 51.

Despite the very low hours, it had been a few years since the plugs were changed, and I just got done installing them this morning (OEM NGK LFR6A). Started up the engines, and both check engine lights re-occurred--not surprising. The engines started right up, idled well, and were both very responsive to throttle (in the garage). I then tried all of the following, to no avail:

1. Started each engine 5 times, turning the key off and waiting about 10 seconds each time.

2. Removed the System/Starter battery cables (positive and negative) and touched them together, then repeated No. 1

3. Tried the procedure outlined by @MidnightRider in this thread: Starboard Check Engine Light Troubleshooting. When that didn't work, I then repeated No. 1.

4. Took the following picture of the "Engine" screen in SYS CTRL (held down)>Test>Engines. I believe the SPN 0 (OBD Diag) Code and the Yamaha Diag Code 1 when the engine is running means everything is normal, but would appreciate confirmation. As you can see on the attached, the only thing showing up as "True" are the "Check Engine Warning" boxes. As an aside, it's great that Yamaha's diagnostics tells you that when you get a check engine light it's because (when you look in the diagnostics) there's a check engine light. Beyond that, I can't figure out what's next short of bringing it to the dealer.

Both battery voltages are good--the thing is always on a dual trickle charger when not in the water. They were both at 12.6-12.8 no load, with the charger and engines off. Over 13 when running at idle (as you can see)

Any further thoughts/suggestions would be appreciated.

Jeff

 

[JDRacing]

Bringing this up to the top, but I'm guessing the lack of responses indicates that maybe there's not much more to try here short of bringing it to the dealer or buying Maptuner to reset it. If anyone has any other ideas, please let me know.

Jeff

 

[Neutron]

I would disconnect both batteries for 15 minutes just to be sure. I see you disconnected the one battery. Other than that you may need to scan the ecu and see what the real code is

 

[JDRacing]

Thank you Neutron. Will give it a try.

Jeff

 

[JDRacing]

Well, disconnected both batteries yesterday and then let it sit overnight. Same issues. Even repeated the 5 starts process without success. It's going to the dealer tomorrow. Thank you for the suggestion Neutron. Will report back on what they find.

Jeff

 

[Neutron]

Please keep us posted, must be a hard code if it wont reset. Like a fauty sensor

 

[JDRacing]

Under normal circumstances I would agree with you, but the fact that I had both engines missing for about 10 minutes while it cleared itself out (because the boat had been sitting awhile) each generating a check engine light, and then both engines cleared and ran great (buy.the lights stayed on), makes me question whether it is a faulty sensor. And then I changed the plugs a few days later. It's hard to believe a faulty sensor would turn on check engine lights on both engines. But who knows. Maybe two O2 sensors failed simultaneously.

Jeff

 

[Neutron]

We will soon see. Good luck

 

[JDRacing]

So, reporting back after the trip to the dealer today. They hooked their YDS reader up and it showed two "Ignition System" codes on the Port engine (Code 233 and 231) and one "Ignition System" code on the Starboard engine (Code 232). The tech was virtually certain this was the result of what he called "rusty spark plugs", which I had changed out last week. If there's rust, it must be up in the insulator, because the plugs looked basically brand new at the central and ground electrodes. But we all know these plugs don't like to be in there for too long.

These codes apparently require hard resets and don't show up on consumer accessible diagnostics. He also said that it "might" have reset if I had taken the boat out and run it for an hour with the new plugs. But not a certainty.

Anyway, he cleared the codes, checked everything over, and 15 minutes after he started, he was done. $142. I guess still cheaper than buying Maptuner.

And I really have no complaints with Tracy Motorsports (Tracy, CA), who was the selling dealer group, and who had done the 10 hour service (before I started servicing the boat myself). They did their best to listen to the whole scenario described in my first post, and got me in and out of there in two hours. Also, the dealer representative who did my walk through when I bought the boat in 2018 (Noah Hulst) and Steven, the service writer, are still there after all these years, which speaks well of the dealership. Plus, there's just something that feels appropriate about bringing in my boat for service to a guy named "Noah".

Thanks again for the input, Neutron.

Jeff