Knock sensor


Information and questions on GL1800 Goldwings (2001-2017)
  • Sponsored Links
Post Reply
miller8090
Posts: 4
Joined: Wed Feb 06, 2019 1:21 pm
Location: Michigan
Motorcycle: 2004 Gl 1800

Knock sensor

Post by miller8090 » Thu Feb 07, 2019 8:10 am



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



User avatar
AZgl1800
Posts: 1803
Joined: Thu Oct 30, 2008 2:46 pm
Location: Lake Oologah Indian Territory USA
Motorcycle: '02 GL1800

Re: Knock sensor

Post by AZgl1800 » Thu Feb 07, 2019 8:29 am

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
What is the Forum Index?
http://bit.ly/2GnjbzV

Download it here:
http://bit.ly/2SLDNqF

miller8090
Posts: 4
Joined: Wed Feb 06, 2019 1:21 pm
Location: Michigan
Motorcycle: 2004 Gl 1800

Re: Knock sensor

Post by miller8090 » Thu Feb 07, 2019 8:36 am

2004gl 1800 178,000 miles. Thanks for imput

User avatar
AZgl1800
Posts: 1803
Joined: Thu Oct 30, 2008 2:46 pm
Location: Lake Oologah Indian Territory USA
Motorcycle: '02 GL1800

Re: Knock sensor

Post by AZgl1800 » Thu Feb 07, 2019 8:41 am

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
What is the Forum Index?
http://bit.ly/2GnjbzV

Download it here:
http://bit.ly/2SLDNqF

User avatar
GoldWingrGreg
Posts: 468
Joined: Tue Aug 24, 2010 7:18 am
Location: Zephyrhills, Florida
Motorcycle: 89 GL1500
03 GL1800
04 GL1800(abs)
05 GL1800(abs)
07 GL1800(abs)
Contact:

Re: Knock sensor

Post by GoldWingrGreg » 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.

miller8090
Posts: 4
Joined: Wed Feb 06, 2019 1:21 pm
Location: Michigan
Motorcycle: 2004 Gl 1800

Re: Knock sensor

Post by miller8090 » Fri Feb 08, 2019 7:48 am

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.

User avatar
GoldWingrGreg
Posts: 468
Joined: Tue Aug 24, 2010 7:18 am
Location: Zephyrhills, Florida
Motorcycle: 89 GL1500
03 GL1800
04 GL1800(abs)
05 GL1800(abs)
07 GL1800(abs)
Contact:

Re: Knock sensor

Post by GoldWingrGreg » Sat Feb 09, 2019 6:18 am

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
Posts: 4
Joined: Wed Feb 06, 2019 1:21 pm
Location: Michigan
Motorcycle: 2004 Gl 1800

Re: Knock sensor

Post by miller8090 » Sat Feb 09, 2019 8:01 am

Thanks for the information.

User avatar
AZgl1800
Posts: 1803
Joined: Thu Oct 30, 2008 2:46 pm
Location: Lake Oologah Indian Territory USA
Motorcycle: '02 GL1800

Re: Knock sensor

Post by AZgl1800 » Sat Feb 09, 2019 8:38 am

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
What is the Forum Index?
http://bit.ly/2GnjbzV

Download it here:
http://bit.ly/2SLDNqF

User avatar
GoldWingrGreg
Posts: 468
Joined: Tue Aug 24, 2010 7:18 am
Location: Zephyrhills, Florida
Motorcycle: 89 GL1500
03 GL1800
04 GL1800(abs)
05 GL1800(abs)
07 GL1800(abs)
Contact:

Re: Knock sensor

Post by GoldWingrGreg » 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 ???

User avatar
AZgl1800
Posts: 1803
Joined: Thu Oct 30, 2008 2:46 pm
Location: Lake Oologah Indian Territory USA
Motorcycle: '02 GL1800

Re: Knock sensor

Post by AZgl1800 » Mon Feb 11, 2019 12:52 pm

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
What is the Forum Index?
http://bit.ly/2GnjbzV

Download it here:
http://bit.ly/2SLDNqF

User avatar
GoldWingrGreg
Posts: 468
Joined: Tue Aug 24, 2010 7:18 am
Location: Zephyrhills, Florida
Motorcycle: 89 GL1500
03 GL1800
04 GL1800(abs)
05 GL1800(abs)
07 GL1800(abs)
Contact:

Re: Knock sensor

Post by GoldWingrGreg » Tue Feb 12, 2019 9:57 am

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.



Post Reply