ECU compatibility question

[Robb235]

What interests me the most is trying to figure out how the low-wake modes work between the boats and the wave runners. For the boats, the service manuals indicate low-wake being activated by a blue/red wires going to the ECU from the Low-Wake switch. This matches up to the blue/red wire at Pin #28 for the boats.

But for the wave runners, Pin #28 is blank. I’m not 100% sure how low-wake mode is activated on the skis. What I do know is that holding “unlock” on the remote transmitter for a few seconds puts the skis into low-wake mode. This means that the remote control box must then send a signal to the ECU commanding low-wake mode. Looking at the FXHO ski diagram attached, there are two wires that connect the remote box to the ECU, yellow at Pin #31 and blue at Pin #14. The yellow at Pin #31 appears to be part of the main relay circuit. I assume that the blue wire at Pin #14 must then be for the low-wake mood for the skis? If it is, then why do the boats use different pins than the skis to activate low-wake mode?

 

[WREKS]

My 2007 SX230 HO service manual shows pin#8 as B/Y, pin#14 as L(Blue), and pin#28 as LB(Blue/Black).
According to Yamaha Sports Plaza, I think I have ECU 6P6-8591A-00-00 (No longer available). 6P6-8591A-01-00 is the replacement.

 

[Robb235]

My 2007 SX230 HO service manual shows pin#8 as B/Y, pin#14 as L(Blue), and pin#28 as LB(Blue/Black).
According to Yamaha Sports Plaza, I think I have ECU 6P6-8591A-00-00 (No longer available). 6P6-8591A-01-00 is the replacement.

Any chance you could verify and post pictures?

 

[Robb235]

My 2007 SX230 HO service manual shows pin#8 as B/Y, pin#14 as L(Blue), and pin#28 as LB(Blue/Black).
According to Yamaha Sports Plaza, I think I have ECU 6P6-8591A-00-00 (No longer available). 6P6-8591A-01-00 is the replacement.

I think those are inaccuracies within the Yamaha service manual. For example, the 2005 FXHO waverunner manual states that Pin #32 is a Black/Orange wire, but in reality it was blank on my waverunner's ECU.

Page 7-13 of the 2007 service manual you sent me indicates two Black/Yellow wires. There is one Black/Yellow shown going to the engine temp sensor, which corresponds to Pin #35. No info shown for where the other Black/Yellow wire, allegedly at Pin #8, goes to. I think the manual is wrong.

Page 7-25 of the same service manual indicates that Pin #14 is Blue, but doesn't show any blue wires coming off the ECU on that page. I think it's an error in the manual. I haven't found any pictures of the boat ECUs where there is a Blue wire at Pin #14. Probably a carry over from the wave runner diagram.

Page 7-13 of the the same service manual indicates that Pin #28 is Blue/Black. The page shows a Blue/Black wire coming off the ECU, but then labels the same wire as Orange/Black in a different location. I think it's another error in the manual.

Attached is one of the better pictures I found on the internet that I used to attempt making the pinout of the boat ECU. As you can see, it's very difficult sometimes to tell which pin a wire is sitting in. For example, if you look at Pin #11 in the picture, it appears that a Pink/Green wire is there, but I'm 99% certain that wire is actually in the pin below, sitting in Pin 33. That's where I had to make some "educated guesses" on what wires were sitting in which pin.

 

[Robb235]

After doing some testing tonight, I am convinced that using a jetski ECU in a boat will mean that the three dummy lights on the tach (low oil, overheat, check engine) will never light up if there is ever an issue.

I’m wrapping up an MR1 swap project on an older XR1800 jet boat using two donor ‘05 FXHO jetskis. The XR has its own stock warning lights on the dash, two overheat lights (starboard and port) and a low oil light (intended for the 2-stroke oil tank). I also swapped in a pair of AR230 tachometers to match up with the MR1 HO motors. I spliced the XR’s stock overheat warning lights directly into the thermoswitches of the MR1s. I then wired up the three tachometer warning lights to pins 23, 24, and 25 of the ECU. I simulated an overheat condition by unplugging one of the thermoswitches and jumping the connector together. This immediately set of the warning light on the stock XR (which I have connected directly to the sensor), but the overheat warning on the tachometer never went off. This tells me that the jet ski ECU doesn’t have the ability to light up individual warning lights like the boat ECU can.
A bit of a disappointing result.

 

[PaulyB]

I have two 6p6 ecus I can sell if you want them.

 

[Robb235]

I have two 6p6 ecus I can sell if you want them.

PM sent.

 

[84rzv500r]

hey Robb235 just found this... I think there are other variations... the most interesting here us that I have two what I thought were jetski harnesses however they more closely map to you boat harness for pins 7 & 8. Ill check all the pins tomorrow however... i have pin 7 blank with a plug in and the B/Y goes to pin 8 and so i believe this is the root cause of my intake temp sensor fault... the 6B6 and 6P6 ECU's both report fault 23... the wires have the right signals presented to the ECU but BOTH harnesses have pin 8 presented and pin 7 blank... also the orange wire that should be on pin 8 is no where to be found. so the harnesses match the jetski harness pinouts you present except for 7 & 8... Im gonna swap 7 and 8 tomorrow and double check all the pins

all the other sensors work as they should and the slant does set the code in the boat ECU

 

[Robb235]

Yeah, I’d try moving the B/Y wire over to pin 7 and see what happens. Which pin is the B/Y sitting in on the harness that’s working?