Living with Code 25/26

[Andrew Shadow]

Not familar with the ST1300 but on the GL1800 performance decrease occurrs with CODE 25/26, a limiting mode is set by the ECU. Its not just an annoying warning light as in CBR100XX where no performance change is experienced with these CODES set.

Honda Service Manual states no change when code 25/26 is present.
Most ST1300 owners report a small loss in power and a corresponding increase in fuel consumption when these codes are present. Some have reported not noticing any change in performance.

 

[Andrew Shadow]

These ECUs have the same basic operastion hardware inside.

I have long thought and have stated that I believe that there must be a common component used broadly by Honda that fails for just the reasons that you have stated.

Good luck with this project. While I fortunately don't have this issue I hope that you succeed for those who currently have no repair option.

 

[oztrax]

Have decided to post our progress just on GL1800 forum for convenience so please follow this thread if you are interested: https://www.gl1800riders.com/thread...2607&nested_view=1&sortby=oldest#post-6162607

 

[oztrax]

As the ST1300 and GL1800 were the last models to change to Gen4 PGM-FI as late as 2017 these are the models most in need of a permanent solution. If any of you are aware of other models with this issue let me know please: already aware of CBR1100XX pre 2008 and Aquatrax F12/F12x jetskis all years (similar engine to the CBR1100XX)

 

[oztrax]

am looking for any faulty ECUs that anyone can donate, alternative is a tune file (.bin) if anyone has had there machine retuned

 

[MidLife]

The failure inside the ECU is the processing device for just the knock circuit, it is possible to replace this component, but nothing to prevent a repeat future failure.

We were told this component was no longer available for the ST1300 ECU?

Some seem to have been able to source the one fitting the GL.

 

[MidLife]

, but nothing to prevent a repeat future failure.

"Dark Sun", from the GL site you are referring to, mentions that a few "Zombie" ECUs came back to life after the rerouting of a ground lead.

Does it mean that the Knock Sensing loop is floating? Am not enough of a sparky to be able to tell from the schematic.

If there is an equivalent to this GL ground lead on the ST1300, could its rerouting help extend the life of the ECU?

 

[MidLife]

This is a simple reflash procedure.

I haven't been able to find anything on any site about a successful remapping of the ST1300 after all these years?

Looks like you'd be the first!

No luck sourcing a defunct 1300 ECU on OZStoc?

 

[oztrax]

its not easy to get but possible

KC2-BO | Component Sense

www.componentsense.com

 

[oztrax]

 

[oztrax]

not the best wiring diagram does anyone have a better one ? this doesnt identify ECU wires very well

 

[rogo]

not the best wiring diagram does anyone have a better one ? this doesnt identify ECU wires very well

Yes. Color coded even.
Check threads under schematics maybe.

 

[Andrew Shadow]

not the best wiring diagram does anyone have a better one ? this doesnt identify ECU wires very well

See if the below will help.

Article [13] - ST1300 - Wiring Schematic | ST1300 Articles

Click the link for a bigger (and more recent) version. The schematics can be downloaded from the Google Docs page, click on 'File', then choose 'Download'. The schematic can be viewed by any .pdf viewer. ST1300/A...

www.st-owners.com

Article [13] - ST1300 - Wiring Schematics for 03-07 Standard | ST1300 Articles

My previous bike's manual had a color coded wiring schematics and it was very easy for follow the wires. After becoming cross eyed looking at the B/W ST1300 schematics, I'd decided to create a colored version. I might have missed a line or a description here or there, so if you happen to see a...

www.st-owners.com

 

[oztrax]

thanks Andrew, need to identify pin outs on ECU, still a bit blurry if someone has a bigger screen or whatever to lidst the pin outs please

 

[oztrax]

OK found one I can read

 

[oztrax]

OK "S" stands for shield these 2 shield connections need to be cut from the PG1 power ground wire, this may be enough to fix the issue, if not connect both shields to a good earth point on engine away from any interference eg alternator. When you pull loom apart you will see a white heatshrink cover about 1 inch by 3/4 inch, remove this and there will be soft rubberised stuff underneath, remove this (i just did it by hand). Then you will see a non insulated crimp with 3 wires combined , cut the shield wires for both knock sensor 1 and 2, one is black the other red with blue stripe/bands. Really need to try this on a bike with the CODE 25/26 issue.

 

[oztrax]

If neither of the above steps work remove LG logic ground B4 green with orange stripe from connector.

 

[oztrax]

So this knock sensor module inside ECU is the failure point, there is one for each knock sensor. they are rare but can be sourced. Problem is replacing this your still back to square one where it will eventually fail in the future. The shield and wiring modifications may prevent or delay this module from future failure. My friend who tunes and reflashes motorcycle ECUs wants to re adjust the knock sensor map in ECU this will stop the module from working as hard and hopefully not fail. These ECUs are not easy to program and have to be done on the bench. Which is why I am asking for donations of any ECUs you may have spare to download maps from and rework maps. Another thing we found are some ECUs are compatible across models, only the programming is different.

 

[RobbieAG]

As the ST1300 and GL1800 were the last models to change to Gen4 PGM-FI as late as 2017 these are the models most in need of a permanent solution. If any of you are aware of other models with this issue let me know please: already aware of CBR1100XX pre 2008 and Aquatrax F12/F12x jetskis all years (similar engine to the CBR1100XX)

So that would indicate that the 2008 and later ST1300 models will still have the problem even though it's a different ECU. At least with those, you can still get a replacement (for now). I was considering getting a later model one if I could be confident that the issue was fixed. It's probably not a good idea to assume that.

 

[Andrew Shadow]

So that would indicate that the 2008 and later ST1300 models will still have the problem even though it's a different ECU.

Honda has released precious little information about the ECM hardware/software for the ST1300, which is why no repair shops will repair them as they can't get the information that they need to do so. Changes were made to the ECM in 2008 as the P/N changed. We strongly suspect that there were changes made to the ECM programming based on comparisons by people who have owned ST1300's with both versions of the ECM. I don't think that anyone knows whether or not there were also hardware changes made to the ECM at that time. There have been post 2007 code 25/26 failures reported, but very few. WIll the numbers increase as they age? Until someone has reverse engineered these ECM's and has the ability to do a comparison of them, or until Honda releases the information, I don't think that we can reliably know one way or the other whether the 2008 and later version will be as prone to this failure as the pre-2008 or not. Until then we will have to wait and see what the passage of time reveals.