Code 25

Joined
Jan 14, 2018
Messages
148
Location
New jersey
Bike
St1300PA
Checked the wires and knock sensors to ecu they were both fine , put a new ecu in and still get code 25 , what to do next ?
 
Did you swap the sensors side to side? That will tell you if one sensor is bad if the code changes. Was your ECU brand new or used? There is no easy way to test a used ECU short of putting it on the bike and seeing if the codes go away. What year is your bike? The ECU problem seems to have gone away with Honda's 2008 changes.
 
If you are lucky;
- a faulty knock sensor.
- a defect in the wiring.
- a defective connector.

There have a few who have fixed it without replacing the ECM, but they are a precious few. In many of those cases it turned out to be only a temporary fix. The code returned later on and they ended up replacing the ECM.

Hopefully you are one of the few and you won't need a new ECM.
 
If you do end up needing a new ECU, consider used. ECU's changed with the 2008 model year, and you need either an early or late one depending on your bike. The P bikes' unit works on all civilian bikes within the two groupings and have been significantly cheaper on ebay than recycled non P bikes*. Be aware that most junk yards do not test the ECU's before putting it up for sale but simply say, 'this came off a running bike'. Make sure you know the vendor's return/exchange policy before you buy.

*Subject to change with no notice.
 
not to challenge anyone's wisdom or experience, but push your computer off your desk a couple of times; it still works, well, that's likely what happened to every still working ECU for sale by anyone that's honest, unless you know with certainty the seller or it's a second bike and you only intend to tool around close to home why would you buy a used one anyway? If I was all in for even a couple hundred bucks on a used one for the albeit large difference I'd spring for the new one if it's available and be glad to have it; it's such a critical part, and it's new and you might have some recourse if it's garbage.
 
In 30+ bike repairs, it has NEVER been one of those three.
That well may be but, there have been at least two or three on this forum who have claimed success with one of those three. That makes it a long-shot for sure, which is why I prefaced this statement by writing that luck would need to be on his side.
 
I JUST came in from the garage from replacing the ECU on my 03, was getting code 26. Wiring was good, knock sensors were good. It survived a 5k rev for 20+ seconds!

By far the most expensive part I've ever installed on anything, short of a Chevy 350 rebuild, and I honestly think the engine rebuild was a tiny bit cheaper!

I saved a little bit of cash on it buying it from partzilla, was $763 from them plus tax. Didn't trust buying a used one.

Josh
 
This below is the article about the codes. Looks like code 25 is the left knock sensor but more than likely it's your expensive ECM.
Good luck....
 
I found on a 2003 st1300 has stored code 26 The bike has a melted connector and right knock sensor.later yr bike has improved heat shield in this area.So everyone saying they need new ecu Needs to look for this before condemning ecu!!!!
 
I found on a 2003 st1300 has stored code 26 The bike has a melted connector and right knock sensor.later yr bike has improved heat shield in this area.So everyone saying they need new ecu Needs to look for this before condemning ecu!!!!

Good observation ...

Keep in mind the title of this thread refers to Code 25, not 26 ... :thumb:
 
No. The Bank Angle Sensor keeps a relay turned on that provides power to a lot of components that keep the engine running.

Can I ask why you thought that it might produce Code 25?

Code 25 and 26 both refer to the left/right knock sensors and there are reports that the table of fault codes show left / right incorrectly.
I just read it now as 'one of the knock sensors - test both'.
 
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I found on a 2003 st1300 has stored code 26 The bike has a melted connector and right knock sensor.later yr bike has improved heat shield in this area.So everyone saying they need new ecu Needs to look for this before condemning ecu!!!!
Of course it's a good idea to check thoroughly before spending $800+ (unless you can find one used) for a new ECU. However, many who have had this code have swapped sensors side to side, replaced one sensor with a new one, and still experienced the fault code. Note that there are at least two different ECU's based on the age of the bike.
 
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