Knock sensor


Information and questions on GL1800 Goldwings (2001-2017)
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miller8090
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Motorcycle: 2004 Gl 1800

Knock sensor

Post by miller8090 »



FI light came on flashed code 25. Rt knock sensor, how big a job to replace. Gl 1800. Thanks


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AZgl1800
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Re: Knock sensor

Post by AZgl1800 »

To my knowledge, no one has ever had a Knock Sensor go bad.
Unless a mouse has chewed up the wiring harness.

Get ready to find a replacement for the ICU.

that is what I and many others have had to do.

you did not indicate what year bike/
2001-2005 all use the same ICU

2006-2010 use the same ICU, AFIK ( don't quote me, but pretty sure that is right )

after that, I have no clue.
~John

2009 Piaggio MP3 250cc

https://i.imgur.com/4SOFPYS.jpg
miller8090
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Re: Knock sensor

Post by miller8090 »

2004gl 1800 178,000 miles. Thanks for imput
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AZgl1800
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My son is going to enjoy it for many years to come.

Re: Knock sensor

Post by AZgl1800 »

miller8090 wrote: Thu Feb 07, 2019 8:36 am 2004gl 1800 178,000 miles. Thanks for imput
I have a 2002, and I bought a 2004 ICU from a bike that ran into a brick wall....
folded the forks back under the engine.

but the ICU survived and is in my bike.
~John

2009 Piaggio MP3 250cc

https://i.imgur.com/4SOFPYS.jpg
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GoldWingrGreg
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Re: Knock sensor

Post by GoldWingrGreg »

miller8090 wrote: Thu Feb 07, 2019 8:36 am 2004gl 1800 178,000 miles. Thanks for imput
Do you have a poor running condition, or it wanting to die at stops, or is there a decrease in mpg ???

Code 25 stands for a right knock sensor. However, the circuit consists or 3 parts, and any of the 3 parts can trigger code 25. The parts are a knock sensor, an ECM, and a wire harness.

One way to help isolate the symptom is to swap the left and right knock sensors, erase the stored code, and wait for the FI light to light again, while retrieving the code. If the new code is 26, then a bad sensor from the right side was installed on the left side. A code 25 means that it is not a knock sensor and probably a ECM.

According to Honda, the ECM for a 2004 is unique to that year.

If the ECM gets replaced, be sure to pull the spark plugs and check them for fouling.
miller8090
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Re: Knock sensor

Post by miller8090 »

Greg. Bike run fine no change in mpg. Once light is reset can ride for a few hundred miles before fi light comes on with no change in performance.
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GoldWingrGreg
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Re: Knock sensor

Post by GoldWingrGreg »

To replace the knock sensor, remove lower center cowl, and right front exhaust shield. Be sure to inspect the rubber mounting caps and the insulated washers help secure the exhaust shield in case some need replaced before ordering in you knock sensor.

The rubbers get torn and the green washers separate. To replace the knock sensor, you will need a 24mm deep socket. However, I believe I use a 15/16" deep with a paper towel stuffed in it so that the knock sensor does not fall into it when threading it back on. The hardest part of replacing the sensor is releasing its connectors push point.
miller8090
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Re: Knock sensor

Post by miller8090 »

Thanks for the information.
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AZgl1800
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'02 GL1800 lives in Dawsonville, GA now.
My son is going to enjoy it for many years to come.

Re: Knock sensor

Post by AZgl1800 »

GoldWingrGreg wrote: Fri Feb 08, 2019 4:24 am
miller8090 wrote: Thu Feb 07, 2019 8:36 am 2004gl 1800 178,000 miles. Thanks for imput
Do you have a poor running condition, or it wanting to die at stops, or is there a decrease in mpg ???

Code 25 stands for a right knock sensor. However, the circuit consists or 3 parts, and any of the 3 parts can trigger code 25. The parts are a knock sensor, an ECM, and a wire harness.

One way to help isolate the symptom is to swap the left and right knock sensors, erase the stored code, and wait for the FI light to light again, while retrieving the code. If the new code is 26, then a bad sensor from the right side was installed on the left side. A code 25 means that it is not a knock sensor and probably a ECM.

According to Honda, the ECM for a 2004 is unique to that year.

If the ECM gets replaced, be sure to pull the spark plugs and check them for fouling.
on my 2002, swapping the knock sensors had no effect on the code.
We used a DVM with a Frequency measuring option to monitor the leads of left/right sensors at the ECM/ICU connector and then used a small ball pein hammer to tap the engine case down near the sensor. An Oscilloscope would do quite nicely if you have access to one.

Both sensors developed a signal at the ECM....
I seriously doubt there is any significant difference for the 2004 model year, and I bought a 2004 ECM and put it in my 2002 bike, and it solved the problem. It runs perfectly.

as for Symptoms with a knock sensor code? the ECM seemed to go into "Failsafe Mode" and the fuel mileage was always poorer than anyone else on trips side to side. It consistently used 1 gallon more on long trips than other 1800s.
~John

2009 Piaggio MP3 250cc

https://i.imgur.com/4SOFPYS.jpg
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GoldWingrGreg
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Re: Knock sensor

Post by GoldWingrGreg »

AZgl1800 wrote: Sat Feb 09, 2019 8:38 am I seriously doubt there is any significant difference for the 2004 model year, and I bought a 2004 ECM and put it in my 2002 bike, and it solved the problem. It runs perfectly.

It sounds like you are speculating, or do you have the ability to verify ECM programming ???
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AZgl1800
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Re: Knock sensor

Post by AZgl1800 »

GoldWingrGreg wrote: Mon Feb 11, 2019 10:59 am
AZgl1800 wrote: Sat Feb 09, 2019 8:38 am I seriously doubt there is any significant difference for the 2004 model year, and I bought a 2004 ECM and put it in my 2002 bike, and it solved the problem. It runs perfectly.

It sounds like you are speculating, or do you have the ability to verify ECM programming ???
I am going by the Seat of my Pants with the overall performance of the 2004 ECM in my 2002.
runs perfect.
~John

2009 Piaggio MP3 250cc

https://i.imgur.com/4SOFPYS.jpg
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GoldWingrGreg
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Re: Knock sensor

Post by GoldWingrGreg »

AZgl1800 wrote: Mon Feb 11, 2019 12:52 pm
I am going by the Seat of my Pants with the overall performance of the 2004 ECM in my 2002.
runs perfect.
Thanks for clarifying. Unfortunately these are an engineered vehicle, and although for you, you notice no difference in using an ECM that is not designed and engineered for your year, others might. The engineers take into account various riding styles, conditions, and altitudes.
TheTestmans
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Re: Knock sensor

Post by TheTestmans »

Great day question what if your pulling a 25 and a 26 code at the same time? Could this be a harness issue? The codes came in at the same time. I just pulled out to clean it up and took it for a spin. Drove about 10 miles when the F1 came up on dash. Once I got the code it was giving me a series of lights which I determined it was a 25 and a 26 code. I appreciate all you can add.

Thanks
Techdude2000
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Re: Knock sensor

Post by Techdude2000 »

There’s also the possibility that a leaking spark plug wire can be arcing over and zapping the ECM’s knock sensor circuit, the harnesses are in close proximity to each other at the front of the heads. Make sure you have no leaking wires by running it in the dark while spraying a water mist on the plug wires.
TheTestmans
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Re: Knock sensor

Post by TheTestmans »

Ok Awesome Information. I will look into this as well. Thank you so much for this Information. I will update on my findings.
collinsa
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2019 CB500X

Re: Knock sensor

Post by collinsa »

This problem arose a month ago and I replaced the RH Knock sensor and all was good until yesterday.
Rode 400km without problems and then the FI light came on - code 25.
FI will go off when shut down and it takes about 40 km before FI comes on again after restarting when hot.
After a cold start it takes about 70km before FI comes on.
On the way home today the engine started to falter occasionally but then settled down - FI was still on the whole time

Checked the wiring and there do not appear to be any issues or short circuits, and I would have expected a faulty wiring circuit to show an immediate fault, I guess it must be the ECU
I have noticed fuel consumption has increased slightly > ECU!
The bike has done 236k

Any thoughts?

I live in Australia
Any suggestions as to the best option for locating a used ECU for November 2004 build GL 1800, and what should I expect to pay? (US $)

By the way, I carry a copy of the fault codes in my top box so I can immediately check for anything serious.


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