FI Code 25 Knock Sensor Issue - HEALED!

Kurt0721 said:
so there is one sensor for 2 cylinders. How can it do such a critical function I figured it was an alert and less of a calibration probe. I did not know that the knock sensor Advanced or retarded the timing. Does anyone have the maps that the ECU looks out? And, Can an ECU be re-flashed? Our ecu’s are upward toward $1000 even as high as $1200 . There are ECU’s on every Honda vehicle since 1988 all using roughly the same parts most are in the $300 range ... not the ST1300.
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I contacted most of the salvage yards and they say when they get in a ST ECU they are very proud of them (pricey). Even the Police models .
 
Kurt0721 said:
so there is one sensor for 2 cylinders. How can it do such a critical function I figured it was an alert and less of a calibration probe.
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yes. 2 cylinders fire at the same time, sounds strange but when the one coil fires one cylinder is on compression and the other fires on exhaust. The ECM on the Honda performs a few thousand calibrations a second , the new car ECMs performs millions of calibrations per second
 
Al st1100 said:
yes. 2 cylinders fire at the same time, sounds strange but when the one coil fires one cylinder is on compression and the other fires on exhaust. The ECM on the Honda performs a few thousand calibrations a second , the new car ECMs performs millions of calibrations per second
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Thank you very much you’ve cleared up some things in my head
 
Sorry to jump in and Hijack this thread...but I have recently found a guy on E-bay that thinks he can maybe "fix" this issue for us.
He does the exact same surgery on the Honda Aquatrax 'jetskis' with great success?

Now here is something "new" I found.
Apparently Honda "Jetskis" suffer from code #25 as well?
This guy claims he can fix it?
He describes the same false sensor code we get on the ST...and claims he can "remedy" or disable it.
Sounds like he physically opens it up and is modifying the hardware / circuit board?

He is looking for a few faulty ECUs from ST1300s so he can disect and try to patch them.
Here is his proposal:
New message from: gen-tune (641Purple Star)
Thanks I might sign up to st-owners.com and engage with users. Don't know if I'll time for it. If you want to be a point of contact that would be great this way I dont have to deal with many users.

Things I need:
- Donor ECU
- ECU pinout
- Wiring Diagram

I will attempt to depot the ECU and expose the circuit board, then map out a schematic and attempt to dump the memory from ecu. If memory dump is successful, then I'll patch the ROM, upload, and submit for testing.

Beta testing will be done with 5 members. All members must post results to the forum.

Any users who submit a donor ecu will automatically get my service for free if there is success.
So, if any of you have your old Code 25 or Code 26 ECUs this guy is interested.
Thanks,
And by the way, I just joined the Code 25 club about 1k miles ago and stumbled across this guy while looking for an ECU on Ebay.
Ernie
 
ErnieB said:
Sorry to jump in and Hijack this thread...but I have recently found a guy on E-bay that thinks he can maybe "fix" this issue for us.
He does the exact same surgery on the Honda Aquatrax 'jetskis' with great success?

Now here is something "new" I found.
Apparently Honda "Jetskis" suffer from code #25 as well?
This guy claims he can fix it?
He describes the same false sensor code we get on the ST...and claims he can "remedy" or disable it.
Sounds like he physically opens it up and is modifying the hardware / circuit board?

He is looking for a few faulty ECUs from ST1300s so he can disect and try to patch them.
Here is his proposal:
​
New message from: gen-tune (641Purple Star)
Thanks I might sign up to st-owners.com and engage with users. Don't know if I'll time for it. If you want to be a point of contact that would be great this way I dont have to deal with many users.

Things I need:
- Donor ECU
- ECU pinout
- Wiring Diagram

I will attempt to depot the ECU and expose the circuit board, then map out a schematic and attempt to dump the memory from ecu. If memory dump is successful, then I'll patch the ROM, upload, and submit for testing.

Beta testing will be done with 5 members. All members must post results to the forum.

Any users who submit a donor ecu will automatically get my service for free if there is success.

So, if any of you have your old Code 25 or Code 26 ECUs this guy is interested.
Thanks,
And by the way, I just joined the Code 25 club about 1k miles ago and stumbled across this guy while looking for an ECU on Ebay.
Ernie
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I send a message via Ebay to this guy, because I live close to his shop. Waiting for answer
 
Khav said:
Fast forward to a couple of weeks ago when I pulled the Duchess from storage and went about firing her up. No pulse. The 6 year-old battery finally went to AGM Heaven, so I ordered another as well as a new solenoid relay...it had been stubborn at times the previous season, so I figured I'd switch it out.

I replaced both yesterday after work and took her for a spin. After a little warm-up, I let her breathe a bit and opened her up...and much to my surprise, I was turning 5000 rpm without a hint of the FI light coming on. I ran her up several times for extended periods and...nada. No FI light or hesitation. The engine seemed more responsive, too.
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When mine started throwing the code, it was only after extended time over 4200 RPM (at least half hour), so mainly on HWYs. Then after a few months in storage, no F1 light anymore! But then, after another storage period, it is back with a vengeance, it only takes a few seconds over 4200 for the light to come back on again. Hope it works out better for you!

In broad day light, I often don't even notice it coming on but annoying at night . Am not feeling any impact on performance when it comes on though.
 
I thought these circuit boards were in a bath of epoxy resin ?
Perhaps a certain voltage on the sensor input is all that is required.
Similar results could be achieved by spot of black paint over the FI light.

I'm not saying this is what this fix is about. The phrase 'remedy or disable' seemed to trigger the input on my cynical circuits.
 
jfheath said:
I thought these circuit boards were in a bath of epoxy resin ?
Perhaps a certain voltage on the sensor input is all that is required.
Similar results could be achieved by spot of black paint over the FI light.

I'm not saying this is what this fix is about. The phrase 'remedy or disable' seemed to trigger the input on my cynical circuits.
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Reputable ECU repair shops have tried fixing this ECU before and said they couldn't so am skeptical as well.

Local mechanic says he has ST rider clients who have settled for your "Plan B" (Black paint or tape, or simply ignore) with no adverse effects observed yet.

Before I replace mine, am curious if anybody has ever had a new ECU failing as well? Never seen anybody reporting that...yet.
 
After I sent via eBay a message to Gen-tune they contacted me by Ph.
Once you donate your ECU for the research, it will be no charge, but your ECU will be destroyed in the process.
I'm going to wait and see if they find the "cure for Code 25-26" and then give my ECU for the treatment,
 
Has anyone ever just unplugged their ECU , then plugged it back in? Or unplug it blow on it and plug it back in ? My kids ( now 40 ) had these Nintendo games with these microprocessor cartridges that would occasionally stop working. They would pull them out blow on them stick them back and they worked.
These modules are micro processor boards with memory maps that can be Re-mapped and easily screwed up I’m sure. I have many ham radios that come with similar Re-mapping tools usually done with a laptop and usb cable.
Harleys have tuneable ECU kits even Itchy Boots put one on her Royal Enfield.
There is a guy in SC who has provided extensive info on Honda car ECU’s (yes even Civics have FI problems) there are Russian websites about Honda ECU reprogramming.
Honda has used the same technology since the early 1990’s .
our replacement ECU,s should not be so pricey I think there is some price gouging going on .
 
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Yes. I did it with my ST1100AY. I had been doing something and when I turned on the ignition, the ABS TCS and various other bulbs were flashing on and off randomly and out of synch with each other.

I ducinnected the battery, unplugged the ABC and ECU modules , earthed the cases, left them for a while and reconnected everything, battery last.

Its a case of if you haven't got a clue what you are doing, then having a few straws to clutch at sometimes helps. In this case the straws to be clutched were inspired by the version of Windows available at the time. If all else fails, close windows, Shut down the computer completely and restart.
 
Some have swapped ECUs back and forth on their 1300 (which would count as unplug/plug) to verify their original twentysixied was indeed defective, but this doesn't seem to have helped the original to shape up.
 
Khav said:
Rather than tack this on to any of the many threads on the issue, I thought I'd post a new one as this event seems worthy.

So...about a year ago I noticed that the FI light would come on anytime I ran my '04 above 4000rpm. In addition, the bike would lag.

Digging into the issue, I found that it was throwing a 25 code, so I scoured the forum for potential issues, fixes and advice. From ECU's to harnesses to sensors, a variety of potential causes presented in the forums...the most likely from my horribly optimistic point-of-view was the wiring. I had always noticed that the cowling seemed to hold massive amounts of heat, so it made sense. The fix was also well below the cost of a new ECU, so I decided to try that first. I ordered the sensor pigtails (the cheaper automotive part) and set them aside for a sunny day.

Fast forward to a couple of weeks ago when I pulled the Duchess from storage and went about firing her up. No pulse. The 6 year-old battery finally went to AGM Heaven, so I ordered another as well as a new solenoid relay...it had been stubborn at times the previous season, so I figured I'd switch it out.

I replaced both yesterday after work and took her for a spin. After a little warm-up, I let her breathe a bit and opened her up...and much to my surprise, I was turning 5000 rpm without a hint of the FI light coming on. I ran her up several times for extended periods and...nada. No FI light or hesitation. The engine seemed more responsive, too.

Aside from Divine Intervention, the only explanation I can come up with is voltage...or lack thereof. Either my old battery was not producing sufficient, consistent voltage or the relay was sapping it somehow and perhaps the ECU was becoming unhappy at the slight.

Or...maybe it's just an anomaly and the FI code will return tomorrow. Dunno.

So, as well as wanting to share my cautious elation, I also wondered if anyone had experienced a similar miraculous healing or had any insight.
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I had the same issue but eventually got the FI at 80 mph Im wondering if its a MAP sensor issue.
 
FWIW. I worked with the Gen-Tune guy about a year and a half ago..
Sent him a bad ecu and whatever wiring diagrams and pinouts I could .
The repair wasn't actually a repair, it was just to disable the code from putting the computer into limp mode, essentially making the computer not have a knock sensor function.
,
Talked to him a few times as he was trying to work though the repair, but eventually, he gave up.
 
v8-7 said:
FWIW. I worked with the Gen-Tune guy about a year and a half ago..
Sent him a bad ecu and whatever wiring diagrams and pinouts I could .
The repair wasn't actually a repair, it was just to disable the code from putting the computer into limp mode, essentially making the computer not have a knock sensor function.
,
Talked to him a few times as he was trying to work though the repair, but eventually, he gave up.
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Thanks for the follow up reply. Too bad he couldn't repair the ECU.
 
The repair wasn't actually a repair, it was just to disable the code from putting the computer into limp mode, essentially making the computer not have a knock sensor function.
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I have no idea about the jet skis, but in the case of the ST1300 I am even doubtful of that. Given the lack of information and data made available by Honda about these ECM's, and that this failure code does not really launch a traditional limp mode, my suspicion is that it is more likely that all they would be able to do is prevent this failure from turning on the FI light. It would seem that even that was not possible as they gave up.

This does not really surprise me either. Every source that repairs ECM's that I have seen has stated that they have no software, parameters, data of any kind available whatsoever on this particular ECM, as a result they have no information upon which to investigate or develop a repair. Honda just will not make any information available even to these repair facilities.
 
Dynojet used to make a power commander for the ST1300, I wonder if enough folks contacted them, they would consider bringing it back?
 
pearlsteinp said:
I've looked over this sight to solve problems in the past, both with a st1100 and my current st1300 .I'm not really a joiner so here goes... I'm an electronic engineer with 35+ years in machine control and repair .I've followed the code 25/26 thread out of curiosity-and I may have noticed the common thread in the failure. Higher operating temps lead to greater fuel trim / a thinner mix at speed leads to higher snap KV requirements with less soak between pulses(4k rpm commonly noted). If the filtering on the supply to the ecm becomes degraded then noise from the ignition secondary could invade and partially swamp out the a/c signal coming on the knock sensor input / by piling the noise onto the ground reference.I would recommend a shunt on the ecm ground to observe outside interference(scope) and choking or filtering any circuits with similar frequencies to the noise .An additional filter or choke to recover faded noise rejection would be cheaper than a new ecm. High difficulty level with potentially high reward. I live in cleveland area and would be interested at seeing this problem 1st hand .Good luck/testing and filter design are electronics 101.
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Wow!!! I would ask that you build something with installation instructions for us mortals to install!! You could solve a major problem and make some money. Frankly I’m considering getting rid of my ST before this problem pops up and turns my bike into a worthless lump….ECU’s are essentially unavailable.

Thanks.
 
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