Multiple codes DF250ap

[seameafterclass]

I have been getting multiple codes on my boat when I first take it out. Typically starting with an 8-3. Turn off motor and battery, turn back on and start and get 7-5, turn off motor and battery, turn back on and get check shift control. There is a “D” on the gauge below the code too. After I turn off the motor and battery switch that time, it typically resolves. I took it to the dealer 2 times and after $500 to diagnose and replace the battery cables and connection terminals in the bilge, it’s doing it the first time I take it out. needless to say, I am not happy.

also, a few times got overheat alarms within 3 minutes of starting the motor and idling to the channel.

[Murray]

Usually you have a voltage issue, you didn’t mention the shop load testing your batteries. As for overheat, when was the last time the water pump was changed?

[seameafterclass]

I am not sure they load tested them, because they are a scummy dealership that does the bare minimum all the time, then overcharges for non warranty items. But they are interstate batteries and maybe 2 years old. Never shows under 12.3 volts except when using trim when the motor is powered off. They said the ground was stable as was power coming from the batteries into the motor after the new cables added. They assured me this would fix the issue.

[seameafterclass]

Another question, maybe related to this, maybe not. When running at my usual cruise speed/rpm, there is an audible change in engine sound and the rpms change, fuel consumption increases and speed drops. Sometimes it snaps out of it and starts working again, sometimes it doesn’t. It goes from 4100rpm at 31mph and 3.5mpg to 3800 rpm 22mph at 2.5mpg, then back to 4100 at 25mph and 2.5 mpg... very odd running behavior. I can’t tell if the sound change is the variable valve timing, or what, but it doesn’t run rough or anything. This issue could be caused by?

[Moonlighter]

If you search this forum there are many posts regarding engines throwing multiple false codes. Almost all are due to electrical issues.

- bad batteries
- bad battery leads
- corroded connections
- white wire compromised either bad connections or internal corrosion
- main battery switch compromised
- and lastly, damaged engine harness somewhere between the engine snd controls. Need to check all joins and connections in the harness and anywhere the harness passes thru bulkheads etc should be inspected to look for places it may have worn through or been nicked.

And yes, poor voltage supply to the ecu can lead to engine running badly as well.

I would definitely have the starting battery load tested as the first job.

[artdf175]

I had something with multiple errors occur last fall
I just rewired with new batteries
You should first read my "sticky" on the "white wire".
In the process rewired for a separate battery switch to run the house wiring side...
well low and behold - the wire connection to the infamous white wire came apart in my hands. now mind you the butt joint connection was the waterproof type.
bottom line-- late last year was getting all the various errors to pop at the same time -- not possible except with a bad wiring.
Start snipping out and replacing butt end connections .. start with the white wire and I suspect you will fix the problem.
Art

[seameafterclass]

Update: the dealership believed it was the wiring harness, due to a spotty ground connection when the key switch was engaged. So they replaced the harness (I thought it was the whole thing due to their wording on the bill and the part number, but it’s only the one on the motor they replaced).
Upon taking it out, boom, codes again and now a 3-6, oxygen sensor. Upon further inspection at home, the main wiring harness, from the motor to the helm about 2 feet down the harness, the wires are brownish tinted and very hard, almost crunchy. So after a discussion with the dealer and dropping it off again, they are going to sea trial it, and bring an extra harness to see if that fixes it. Is this harness covered under warranty? One would think, since it’s essential to the functioning of the motor, but according to the warranty guide “external harnesses” are not covered. I am not sure if that’s referring to nema connections, or the accessories like the binnacle and the gauges. I only ask because I am tired of throwing money at possible fixes, and this is one I can do myself in under an hour.