code 26

[rsc4526]

Need help, please. 04 GL 1800 non ABS. In July FI light came on, put side stand down, get code 26, left knock sensor. If I stop and shut off engine light will not come back on for at least 40 miles, sometime hundreds of miles. It's gotten worse, now it's every time I restart. I swapped left and right knock sensor, removed the terminal from the connector and tightened the terminal so it will contact the prong better on the sensor and ecu side, ohm tested the wire for short to ground or short to power, and cut the wire at the sensor and ecu and ran an outside wire. Swapped right and left sensors again. Light comes on immediately above 2500 RPM. And I remove the battery terminal between each test or swap so the code is cleared.
Another thing, I don't know if it's significant. If I jump the connector under the seat for the codes I get a 26, but also a 41- gear position switch. I will NOT get the 41 putting the side stand down. I have done all the test per the Honda service manual and all test good. Also, everything works proper; cruise, reverse, OD indicator, side stand down indicator, etc. Any help is appreciated.

[WingAdmin]

Need help, please. 04 GL 1800 non ABS. In July FI light came on, put side stand down, get code 26, left knock sensor. If I stop and shut off engine light will not come back on for at least 40 miles, sometime hundreds of miles. It's gotten worse, now it's every time I restart. I swapped left and right knock sensor, removed the terminal from the connector and tightened the terminal so it will contact the prong better on the sensor and ecu side, ohm tested the wire for short to ground or short to power, and cut the wire at the sensor and ecu and ran an outside wire. Swapped right and left sensors again. Light comes on immediately above 2500 RPM. And I remove the battery terminal between each test or swap so the code is cleared.
Another thing, I don't know if it's significant. If I jump the connector under the seat for the codes I get a 26, but also a 41- gear position switch. I will NOT get the 41 putting the side stand down. I have done all the test per the Honda service manual and all test good. Also, everything works proper; cruise, reverse, OD indicator, side stand down indicator, etc. Any help is appreciated.

You've done absolutely everything correct, every step you've taken is exactly what I would have done to diagnose the problem.

Unfortunately, the problem you're experiencing is a common symptom of a bad ECU - and the fact that you've done everything but replace the ECU, I think I'm pretty safe in saying your next step is to source a replacement ECU.

[reggiefavre]

Have you checked all ground connections. I am talking all of them. So much of that bike is plastic.

[rsc4526]

A few weeks ago I asked everyone's opinion on a code 26 on my 04 GL 1800 non ABS. It turned out to be the ECM as suspected. However it was a little hard to find. Most places said it was backordered, with an unknown arrival date. A dealer in

Texas had one in stock, but at full retail, $560. Partzilla finally got one for $377, but took about a month. That's alright, I was in no hurry, and the bike ran like it was. Everything is good now. Thank you all very much!! Merry Christmas!

[WingAdmin]

Good news! Glad you got it worked out. You did the exact correct method of diagnosis, and as a result found the problem and got the bike fixed.