I have a 2006 honda non-turbo Thats showing limited and throwing FI code 25

[mrjetskey]

I understand this code is for engine knock sensor, This ski ran fine this year maybe 5 times for total of 8 hours. According to owner. oil and filter were changed about 10 hours ago. Seeing as how its knock sensor code. I changed spark plugs they were carboned up a bit.I also checked oil level its right on .Ski has 60 hrs total.Is it possible for bad fuel to cause knock sensor to trip code? (it happened about 30 min. after owner had bought fuel. It looks ok ,I don't know Hondas very well at all and there is no one around here who does.Any ideas from Honda owners who have seen or had this problem??? I'm kinda lost as it runs awesome until it goes into limp mode.( owner does not remember limited being lit before) It stays on in black letters . Many thanks in advance.

[DSR]

Hi there,

I'm not an Aquatrax guru by any means, but I'm pretty comfortable with ECU-controlled engines and learned quite a bit while researching my own project, so here goes nothing.....

If it was caused by bad gas, I would think you would have some "driveability" issues before the limp mode kicked in, but it doesn't sound like that's the case? If the gas was bad enough to kick the knock code it would probably run like crap, if at all.
2) knock sensor. Possibly, but judging by what I've found, they're pretty robust units and they don't fail very often. They are way cheaper than an ECU though to start with.
3) ECU. Based on everything I've run across, this seems most likely. I just saw a post on PWCToday that Gen-tune evidently found a way to cure the code 25 in the ECU. Judging by what he wrote, it sounds like he physically breaks into the ECU housing and removes the faulty component that causes the code to pop (it also sounds like it might disable the knock sensor function permanently?). On a turbo ski, I'd be a little concerned about doing something like that, but not so much with the N/A engines. It might be worth talking to him if the ECU is in fact the problem....

Just my 2 cents

Thanks,
Dave

[NitroShark]

Get an owner's manual out and be sure it's not in "limit mode". Next check the service manual and look up the service test for code 25- do the procedure and report back.

[mrjetskey]

Get an owner's manual out and be sure it's not in "limit mode". Next check the service manual and look up the service test for code 25- do the procedure and report back.

Yes it was in limit mode ,I work on yam., kawas, and seadoo,only seen about" 4 Hondas in last 10yrs and that was for oil change and service". It now instantly only goes to 3k rpm. I pulled code its 25 like before do the knock sensors go bad on low hr skis? I know anything is possible but is this the norm for Hondas, . Do these need to be reset with Honda code shorting tool if fault has occurred ?? , I will ohm out the sensor and check wiring to it ? Many thanks in advance for your help.!!!!!

[mrjetskey]

Well heres what I found out according to service manual tests the knock sensor is ok and the blue wire has continuity from end to plug on ecm also no grounding of said blue wire. How do I erase fault memory without Honda pocket tool, I thought I had read somewhere it was possible to use just a jumper, however either I'm searching wrong place or ?????. Thanks for help so far

[NitroShark]

To reset, you use the "service check connector" and jumper 2 wires. You will need to look in the service manual and wiring to find which colors for your year (2006) ski.

You said the ski is in Limit mode? That is an optional feature (limits RPM) that is used for beginning operators and can be turned on and off with the "mode" button on the dash refer to the owner's manual for this procedure.

[mrjetskey]

Nitro perhaps I didn't get my post across . It was in limit mode, I removed limit ,it has fault 25 , ran through tests all looked ok, I ordered the sending unit and replaced same. Now code FI 25 has changed to FI 9 So ill keep post updated after this next step!! Yes I checked the IAT sensor plug and connection, will update!! at least 25 isn't showing now!!!!!

[mrjetskey]

my question is this once Honda throws a code ,if the fault causing code is repaired? Does the FI need to be reset with jumper or will it reset itself. I didn't understand that part. Thanks

[mrjetskey]

Well I'm sure all the Honda fans knew the outcome of this when I first mentioned FI25 what gets me is I have a couple customers who have 2006 Hondas one has a red set the other a blue pair. They have over 250+ hrs, and other set in the 300+ hours, no problems , yet here is this trailer queen with 60 hrs needing a Fi controller or CPU. Doesn't make sense but it must have something to do with perhaps batteries going dead or non use. I know on occasion electronics go bad but the amount of controllers that has seemed to go bad is unreal. They must of had a bad run or just certain ones ????? Who knows .I do really like the Honda design and engine!!!

[West_Coaster]

If the battery is hooked up, the ECU is receiving/consuming power. Granted it's a small draw to see if the lanyard is present, but who knows what else is going on inside the ECU.

I believe it's best to disconnect the battery when you're not using the ski.

If the 300+ hour ski disconnects the battery, and the 60 hour ski doesn't, that could explain why the 60 hour ski has the ECU problem.

[mrjetskey]

Just for info I have asked both owners the 300hr and 250hr skis always keep battery connected and charged. As for the 60 hour trailer queen battery was always connected but allowed to fail twice so who knows the one has always had fresh batts and the low hr. had batteries go dead. So perhaps it is FI controller receiving less than 12.25 volts that caused failure. My guess is a faulty layer in board.???????

[DSR]

FWIW, the X that I picked up for my project had actually set outside at a salvage auction facility since 2013 and I picked it up in Oct. 17 (with the battery completely dead of course....), I replaced the battery, changed oil and filter, purged the fuel system and it fired right up with no drama.

From what I've gathered, I think the Honda ECUs are inflicted with the same issues that most production OE components are, in that they're built to a price-point set by the OE, and hence not as robust and reliable as they could have been. Keihin evidently cut the line a little too close in that compromise......

[mrjetskey]

I can say this ,other than the oil checking routine (Yamaha 5 valve and all dry sump must be run before seeing proper oil level) and the FI controller as Honda labels it. The HONDA'S are awesome engines and are very tough all things considered, and one heck of tough turbo.

[DSR]

I definitely agree that Honda did a nice job on the engine architecture / design for their PWCs and the quality of the components within. A couple of the reasons that I chose an R12X for my mini jet boat project. A 1235cc DOHC 4-cylinder with forged internals and dry-sump oil system and a 6600 rpm redline, with proper maintenance, should last darn near forever. Even with a 7500-8000 redline and reasonable additional boost using a stand-alone engine management system that I'm planning on utilizing, should be well within the capabilities of the design with a valve spring upgrade, which seems to be the only "weak link" in these engines when you turn the wick up on them

[Gen-Tune]

I can say this ,other than the oil checking routine (Yamaha 5 valve and all dry sump must be run before seeing proper oil level) and the FI controller as Honda labels it. The HONDA'S are awesome engines and are very tough all things considered, and one heck of tough turbo.

Hey Marvin glad to see you got this solved, You emailed me a while back about the issues you had with the Code 25