code 25

[R Robbins]

HELLO I HAVE A 2003 GL1800, THE FI LIGHT COME ON AFTER DRIVEING FOR A HOUR OR MORE, CHECK FLASHS ON FI LIGHT AND GETTING CODE 25. I HEAR NO KNOCKING IN THE ENGINE AND IT RUNS FINE. CHECK WIRES AT THE KNOCK SENSOR AND THEY LOOK OK CHECK SPARK PLUGS OK .PLUG WIRE NOT ARKIN THAT I CAN SEE AT NIGHT, CODE STILL COMES BACK AFTER DRIVING FOR A WHILE HOUR OR MORE.HAS ANY BODY ELSE SEEN THIS BEFORE. ANY SUGGESTIONS PLEASE
PS I ALSO NOTICE BEFORE THIS THE CRUISE CONTROL IF SET WHILE DRIVING ON TRIPS WOULD SHUT DOWN AND THE EGNINE WOULD STALL LEAVE CRUISE OFF AND ENGINE WOULD STAYED RUNNING. IBEEN RUNNING THE BIKE WITH CRUISE OFF IT'S BEEN RUNNING FINE INTILL NOW NOW CODE 25 SETS STIIL RUNS FINE.

[AZgl1800]

my 2002 had the Fault code for Left Knock Sensor.

Monitoring the leads AT THE ECM with a Frequency Meter ( Oscilloscope would be better )
proved that the ECM was bad.

the DVM gave forth with a lot of fast moving waveforms and tiny little voltage readings for both sensors, when tapping the case with a small Ball Pein hammer.

I lucked out, found a 2004 ECM from a wing that met a brick wall, it works perfect

improved the MPG from the 22-26 range to the 36-40 range.

[R Robbins]

thank you for the info I will check that out. thank you again

[Techdude2000]

HELLO I HAVE A 2003 GL1800, THE FI LIGHT COME ON AFTER DRIVEING FOR A HOUR OR MORE, CHECK FLASHS ON FI LIGHT AND GETTING CODE 25. I HEAR NO KNOCKING IN THE ENGINE AND IT RUNS FINE. CHECK WIRES AT THE KNOCK SENSOR AND THEY LOOK OK CHECK SPARK PLUGS OK .PLUG WIRE NOT ARKIN THAT I CAN SEE AT NIGHT, CODE STILL COMES BACK AFTER DRIVING FOR A WHILE HOUR OR MORE.HAS ANY BODY ELSE SEEN THIS BEFORE. ANY SUGGESTIONS PLEASE
PS I ALSO NOTICE BEFORE THIS THE CRUISE CONTROL IF SET WHILE DRIVING ON TRIPS WOULD SHUT DOWN AND THE EGNINE WOULD STALL LEAVE CRUISE OFF AND ENGINE WOULD STAYED RUNNING. IBEEN RUNNING THE BIKE WITH CRUISE OFF IT'S BEEN RUNNING FINE INTILL NOW NOW CODE 25 SETS STIIL RUNS FINE.

If you swap the knock sensors side to side and then it throws a 26 code, it’s a bad sensor. If it still throws the 25 code, it’s most likely a bad ECM

[R Robbins]

thank you I will try that

[bstig60]

I have had this failure on my 2007 ST1300. ECM was the culprit, I was lucky enough to find a used one from a 2003 ST and replaced it and no problems since, that was 2 years and over 12k miles ago. No problem with my GW yet.