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ECU compatibility question

ninjakris

Member
Messages
17
Reaction score
14
Points
12
Location
Destin, FL
Boat Make
Yamaha
Year
2005
Boat Model
SX
Boat Length
23
Hello. I have a 2005 SX230 HO and currently one of my ECU's is off getting the injector output repaired (at least I'm 99% sure thats my issue). While I've been waiting for that to be repaired and sent back, I happened to pick up a pair of 05 yamaha FX cruisers with the HO motors. One of them is a runner but the other one has a bad motor and is being used for parts. That leads me to my question. Can I use the ski ECU in my boat? In my mind, it should work but I'm hoping someone here may know for sure.

BOAT ECU: 6P6-8591A-01-00
Jet ski ECU: 6B6-8591A-10-00
 
Hello. I have a 2005 SX230 HO and currently one of my ECU's is off getting the injector output repaired (at least I'm 99% sure thats my issue). While I've been waiting for that to be repaired and sent back, I happened to pick up a pair of 05 yamaha FX cruisers with the HO motors. One of them is a runner but the other one has a bad motor and is being used for parts. That leads me to my question. Can I use the ski ECU in my boat? In my mind, it should work but I'm hoping someone here may know for sure.

BOAT ECU: 6P6-8591A-01-00
Jet ski ECU: 6B6-8591A-10-00
Did you try it?
 
I have heard that they are not interchangeable because the skis have a roll over switch that the boats don’t have and you will get a constant alarm.
 
@Brad_Ct The YDS brings up the roll over switch status on my boat each time I hook it up. Fortunately it has never documented I rolled my boat over.
 
@Brad_Ct The YDS brings up the roll over switch status on my boat each time I hook it up. Fortunately it has never documented I rolled my boat over.
So does mine but I don’t think it actually exists on the boats. I had asked the same question awhile back about them being interchangeable because I have a ECU out a FX140 ski and was told they are not. It is very possible that the information I got was incorrect though.
 
I recall reading the no wake speed switch function did not work when someone on this board used ECU and Engine from Ski, then switched to Boat ECU and it restored No Wake. I do not remember where or how long ago I read that, so It could be made up in my brain, but I would swear today I remember it as being true.
 
Short answer, yes it will work. The only issue you'll see is on your gauge cluster, you'll get an intermittent light blinking due to the 2 codes. This will in no way limit or prevent anything mechanical from working. There's no beeping of any sort. Just a red light blinking on the dash. Just make sure everything else is in check ( oil, temp and etc)
 
Short answer, yes it will work. The only issue you'll see is on your gauge cluster, you'll get an intermittent light blinking due to the 2 codes. This will in no way limit or prevent anything mechanical from working. There's no beeping of any sort. Just a red light blinking on the dash. Just make sure everything else is in check ( oil, temp and etc)
Do you know what the fault codes are related to?
 
Short answer, yes it will work. The only issue you'll see is on your gauge cluster, you'll get an intermittent light blinking due to the 2 codes. This will in no way limit or prevent anything mechanical from working. There's no beeping of any sort. Just a red light blinking on the dash. Just make sure everything else is in check ( oil, temp and etc)
how did you come to find this out ? do you have personal experience with switching ECU's ??

Just want to understand the whole picture before I start quoting your info in future conversations,


.
 
how did you come to find this out ? do you have personal experience with switching ECU's ??

Just want to understand the whole picture before I start quoting your info in future conversations,


.


Yes, I've used jet ski ecu's for a short term while waiting for my boat ones to get rebuilt. Had absolutely no issues but, I believe the post above was correct that you lose no wake mode.
 
Do you know what the fault codes are related to?

First code was for tilt and the other was steering angle if I'm not mistaken. I actually have a jetski ecm laying around. In a few weeks, I'll make a quick video with the data cable log showing all the values. The most important thing to keep in mind is both ECU's have to be from a HO or Non HO. Shouldn't mix match the two.
 
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Yes, I've used jet ski ecu's for a short term while waiting for my boat ones to get rebuilt. Had absolutely no issues but, I believe the post above was correct that you lose no wake mode.
First code was for tilt and the other was steering angle if I'm not mistaken. I actually have a jetski ecm laying around. In a few weeks, I'll make a quick video with the data cable log showing all the values. The most important thing to keep in mind is both ECU's have to be from a HO or Non HO. Shouldn't mix match the two.

Would you be able to take pictures of the wires going into your ECU connector? I have two HO MR1 engines and ECUs from jetskis, but I want to see what the wiring to the ECU looks like on the boat harness. Goal is to compare the boat vs jetski.
 
They are the exact same. Even the black box is exactly the same. The only difference is the ski ecu box has one extra sensor in there which I believe is for tilt. I'll make a thread and tag it over here
 
They are the exact same. Even the black box is exactly the same. The only difference is the ski ecu box has one extra sensor in there which I believe is for tilt. I'll make a thread and tag it over here
I believe there are more differences in the wires going to the ECU connector than just the tilt sensor for the skis. The boat ECU I believe has some extra outputs to activate the 3 warning lights on the the tach, whereas the jet ski multifunction meter only used the white data wire to read the data stream from the ECU (the same white wire that YDS uses).

Would it be possible for you to take pictures of your boat’s ECU connector (the wires going to it) so that I could study the difference between the boat and jet ski?
 
Ok, so I searched the forums for pictures of people’s boat ECUs. I found a couple pictures where I noticed differences between my jet ski ECU wiring harness and the pictures boat ECU wiring harness.

So on the jet ski harness, pins 23, 24, and 25 are blank. But as you can see on the pictures I found and marked up, the boat harness utilizes those three pins. From what I can tell, it looks like Pink/Black for pin 23, Pink for pin 24, and Blue/ White? for pin 25. I wonder if those pins are what light up the dummy lights on the tach.

F4AD755E-BDF6-4921-A071-AE807C9CE9B6.jpeg3F04930B-F62E-4592-8DEA-6EFDD28C14D9.jpeg
3F04930B-F62E-4592-8DEA-6EFDD28C14D9.jpeg
 
I am not sure if these pictures help but here is a 2008 ECU. IMG_2904.JPG
IMG_2907.JPG
 
Ok, so after looking at the wiring diagram in the service manual and comparing it to my jet ski engine/ECU that is sitting on my work bench, I believe I have a pretty good pinout of the jet ski ECU that I've put into Excel. I then found as many pictures as I could on the web of the boat ECU version. I compared what I saw, and also put that into Excel. In some cases, I had to make some educated guesses, but I think what I have compiled is probably accurate.

MR1 HO ECU Pinout.jpg
 

Attachments

@Robb235 Thanks very much for the pinouts. Very interesting seeing ignition coil#1 located by the probable three warning lights.
 
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