Df300 random electrical issues and codes

[TJHaleen]

Wondering if any has had similar issues and what the solutions were. I have one engine (starboard) that has an intermittent problem where it just won’t turn over. When this happens it gives me a 2-4 code (CKP sensor). If I take a small wire and jump the starter solenoid while holding the start button it fires right. It might start several times on its own but after awhile the same thing happens and I have to jump it.

the second problem I’m having is with the port engine. Starts fine, runs fine but it also randomly ( at idol) gives me an overheat alarm. It is not overheating but it puts it into that limp mode. If I shut it down, kill the power, and then restart it will run fine at any speed. I can run it as long as I want but when I’m I idoling it around to dock it usually acts up. I replaces the temp sensor but that didn’t help. Anyone have any info on either issues? Thanks!

[Moonlighter]

I would be having a serious look at the boat’s electrical system. These engines DEMAND good power supply and if they dont get it you will get starting problems, running problems, false fault codes etc…. Sound familiar?

You may have corroded battery cables, a deteriorated battery, dirty connections, corrosion in a harness…. Start at the batteries, go from there. Check the white wire and the fuse in it, fuse holder might have water got into it,

[TJHaleen]

I know you are right, this boat has been an electrical nightmare for me. I have been working every day on it. I replaced all batteries and battery cables (starting and house) all shutoff switches, almost everything. I have not touched the engine control wiring at the helm station except for replacing the fuse holder on the white wire. Harness corrosion is very possible, even likely. This boat is 20 yrs old and I’m finding that I need to replace every pump on it so I’m really not surprised after hearing how sensitive these motors are to voltage that the wiring is the culprit. I will investigate the harness wires next. If you have any other suggestions I would love to hear them. Thank you!

[Moonlighter]

Of course it could also be an issue with the starter motor itself!

I think there may be 2 temp sensors?? Do some checking.

They do also create 2 kinds of temp alarm,
one is Temp Absolute = engine reaches preset temperature too hot.
other is Temp Gradient which happens when engine temp increases too rapidly, but has not yet reached Temp Absolute level.

SDS system will show which one it is. This can help point to what the problem may be.

If you do replace the water pump, dont skimp and just do the impeller - do a full water pump kit.

Have a look at the wiring around the ecu, look for any corrosion in connections/plugs or damaged wires.

[redlowrey]

Wondering if any has had similar issues and what the solutions were. I have one engine (starboard) that has an intermittent problem where it just won’t turn over. When this happens it gives me a 2-4 code (CKP sensor). If I take a small wire and jump the starter solenoid while holding the start button it fires right. It might start several times on its own but after awhile the same thing happens and I have to jump it.

the second problem I’m having is with the port engine. Starts fine, runs fine but it also randomly ( at idol) gives me an overheat alarm. It is not overheating but it puts it into that limp mode. If I shut it down, kill the power, and then restart it will run fine at any speed. I can run it as long as I want but when I’m I idoling it around to dock it usually acts up. I replaces the temp sensor but that didn’t help. Anyone have any info on either issues? Thanks!

All you are doing is proving that the starter will crank and start when bypassing the system, the starter will crank with out pressing the start switch jumping it, it just won't start because there is no input signal to the bcm end ecu.
You need to find what is happening from the shift leaver signal voltage to the bcm ecu and shift leaver motor and relay, as well as the starter relay.

As far as the over heat goes, I said to you three weeks ago there are three sensors, two exhaust and one temp senor in the system, check the voltage on them when it is hot, for it to go into over heat shut down one of them must be dropping below 150mv. Or you are starting to get ghost voltages from bad communication between the bcm and ecu.
Do you know how to test the can high and can low system, have you got any equipment fast enough to see the packets of data being transmitted.

[TJHaleen]

I have a friend who is a good electrical guy and he has better test equipment then I do. He will help me check the voltages when it is hot. I don’t know how to check the can high and can low stuff but he might. I will ask him. Thank you.

[redlowrey]

Mate I think you need to get your self a work shop manual for this one, even though if the engine stops for some reason, the ecu should shift the gear box back to neutral regardless of where the shift leaver is.
The shifter only sends different voltages to the ecu bcm depending on what position the shifter is in.

It could be as simple as the neutral switch not closing properly or the starter relay or it could be more complicated. It should throw a code if the shift leaver voltages differ.
If you had a faulty crank sensor, the engine would have to turn over and rotate for the ecu to know that the sensor was not working, the engine would not start but it would turn over and throw a 4.2 code.
is that what you mean or do you press the start button and nothing happens.

[TJHaleen]

I got the random no start issue figured out. I need a new shift position sensor. But the random overheat warning is still a problem. I tested all three sensors and they are within specs. I also switched each one of them, one at a time with a brand new sensor and ran it until the overheat came back on so I don’t think it is one of those sensors. Any idea where are should look next??

[TJHaleen]

So I still get the random overheat alarm on that port engine it’s only after I shut it down from cruising speed into idle or if it just sits at idle for a while. Something new that came up was it went into the overheat mode engine revs up a little bit and then actually corrected itself after a couple minutes of idling. I’m not sure where to go with this one from here. Does anyone have any ideas?

[redlowrey]

Run the engine till it goes into over heat and test the signal voltages of the three temp sensors, one of them must be dropping below 150mv for the ecu to go into over heat shut down, if all three voltages do not drop below 800mv there might be a problem at the sensor interface module get back with the results of the first test.
Does the engine smell hot is it peeing good, from what you are describing now sounds like a cooling issue.

[TJHaleen]

Back to the starboard engine, this is really starting to suck! I was adjusting the shift actuator linkage and I accidentally removed it from the shifter while it was running in neutral.The actuator extended all the way and now I can’t get it to stay lined up on neutral. When I begin the start sequence the actuator moves back until the clutch lever is no longer in the neutral position so just slightly back from neutral. Obviously at this point the engine will not start. If I force the shift actuator forward slightly and hold it there with a screwdriver I can start the engine. I can then shift forward, neutral and reverse no problem. But when I shut it off and try to restart it moves that cluch lever just enough so it doesn’t make contact and will not start. HELP!!!!!!!

[redlowrey]

As I said in a previous post get your self a cd off ebay for ten dollars, they have them for your model you need it, you may have damaged it, it say's in the manual to remove the fuse from the actuator when adjusting the rod.

[TJHaleen]

I’m not sure what CD you are referring to. Is it just a repair manual type? Is it your experience that I will now need to replace the actuator? Thanks.

[Moonlighter]

He is repeating the advice to get the full service manual on CD as per post # 7….

So that apart from anything else, you don’t do more damage by doing things without knowing the implications.

[TJHaleen]

I have the manual I just made a mistake by not taking out the fuse. Can you tell me whether or not you can test the shift position sensor output voltage without a test cord?