ST1300.us.com  

Go Back   ST1300.us.com > Honda ST1300 Forums > Maintenance & Repair > Other

Reply
 
Thread Tools Display Modes
Old September 28th, 2013   #1
Redfish
Donators
 
Redfish's Avatar
 
Join Date: Mar 2011
Location: Prairieville, Louisiana
Posts: 2,801
Rep Power: 110 Redfish is a jewel in the roughRedfish is a jewel in the roughRedfish is a jewel in the rough
Default FI Code 26

Code 26. Two long blinks followed by 6 short blinks. Right Knock Sensor.

Well, maybe. I originally piggybacked this onto another thread but now I think my story deserves its own thread. No, all stories don't have happy endings.

Running the engine above 3900 RPM for 10 seconds will generate this fault code. Instantly power is cut, and fuel mileage plummets. 3900 RPM looks like 72 mph on the speedometer. It is 68 mph on the GPS. This fault will give you 37 mpg at 73-74 GPS mph on the Interstate.

First, if the red FI light in the dash comes on you must read the code. Reading the code is very simple. If you know how. Engine running, FI light on, bike in neutral, lower the kickstand. Then count the blinks. A long blink (1.3 seconds) counts as 10. In my case two long followed by 6 short equals 26.

Your Genuine Honda Service Manual will have a chart telling you what the # of blinks translates into. My bike is an '04 so this is found on pages 5-14 thru 5-16.

A quick and desperate check of this ST forum told me that most often the problem was not the sensor. It is the plug and or wiring breaking down from the intense heat of its location. Cutting off the plug and replacing with a suitable spade connector solved almost everyone's issues.

I removed all the Tupperware from the right side. I unplugged the knock sensor. It is inconveniently located between the exhaust header pipes and the engine block. I checked the plug and it looked fine.

The troubleshooting section of the Honda Service Manual says to check for continuity to ground from the plugs on either end of the wiring harness. Then it says to check for continuity between the two plugs. Basically, you are checking to see if the wire has been damaged and is going to ground or has burned/rubbed/broken in two between the sensor and the ECU. If it is not going to ground and the wire is intact, the problem must be the sensor.

*Problem*
The Honda Manual is WRONG concerning the wire colors for my '04 ST. It clearly states on pages 5-49 and 5-50 that the wire colors are:
Left Sensor Wire-Blue
Right Sensor Wire-Red/Blue
This is not correct for my bike. The manual has two sections for two different year groups. The first is for '03-'07. The second is for '07 and later.
My ST is wired like the '07 and later version. My sensor wires were:
Left Sensor Wire-Red/Blue
Right Sensor Wire-Black

Using the wire colors the manual stated for my year I decided the wire between the sensor and the ECU was bad. I ran a temporary wire and cut/spliced into the wiring harness just ahead of the ECU. Tried running the bike, still got the code. Purely by accident I looked at the section for '07 and later and was able to re-diagnose the wiring.

I wound up removing the left side Tupperware during the confusion phase so I tried running separate wires under the bike to "switch sides" with the sensors. I stuck the stripped ends of #14 wire into the female sensor plugs and used spade connectors to attach the other end of the wires to the sensors. No code. Re-connected the plugs. Got Code. Stuck wires back in, Ran bike. No code. R-connected plugs. Got Code.

Sigh... Plugged left sensor back in. Jammed wire back into female plug on right side and plugged spade connector onto right knock sensor. No code.

Decided the connectors inside the female end were "sprung" out and not making good connection to sensor. I found that the plug (sensor end) was not making a good connection at the sensor. I attempted to use a tiny screwdriver to pry the metal connectors out and...

The plug shattered in my hands. The more I tried to repair, the more the brittle plastic crumbled in my hands. I replaced the plug with a tiny spade connector.







Ran the bike on the centerstand, no code. Fixed it!

Or not...
__________________
Never run out of traction, ideas and real estate all at the same time.
Redfish is offline   Reply With Quote
Old September 28th, 2013   #2
Redfish
Donators
 
Redfish's Avatar
 
Join Date: Mar 2011
Location: Prairieville, Louisiana
Posts: 2,801
Rep Power: 110 Redfish is a jewel in the roughRedfish is a jewel in the roughRedfish is a jewel in the rough
Default Re: FI Code 26

Over the next couple of weeks the 26 Code would re-appear. It was intermittent, it was unpredictable. No correlation to humidity, weather, temperature, or bike temperature could I find. I lost confidence in my ST and in my own troubleshooting skills. I began to doubt myself and my bike. I need to have confidence that if I have to I can get on my motorcycle Right This Minute and ride it Coast to Coast. If I can't trust the reliability of the bike, I don't need it.

I removed the Tupperware several times to check my connection. I removed and re-connected the ECU several times. I double checked everything.

I decided that the resistance of the wire between the new spade connector and the plug at the ECU was too high. It is at most 5-6 feet of wire but there was about 4 ohms of resistance in that short length of wire. I would have expected 0.4 ohms, not 4.0 ohms. I replaced the factory wire by running a separate length of wire with a high temperature insulation. I felt confident. Ran on centerstand, no code! Success!

Well, no. Continued to get code intermittently.

Now I am so depressed and disgusted that I am making everyone around me miserable. The ST is such a huge part of my identity and thinking that I am more affected than I ought to be. Yamaha announces the '14 FJR in Candy Red. Factory Cruise Control, electronic suspension, traction control, heated grips... Oh man, things are getting bad. Mrs. Redfish finally says, "I know you don't like giving up but...have you considered buying a new bike?"

__________________
Never run out of traction, ideas and real estate all at the same time.
Redfish is offline   Reply With Quote
Old September 28th, 2013   #3
Redfish
Donators
 
Redfish's Avatar
 
Join Date: Mar 2011
Location: Prairieville, Louisiana
Posts: 2,801
Rep Power: 110 Redfish is a jewel in the roughRedfish is a jewel in the roughRedfish is a jewel in the rough
Default Re: FI Code 26

I removed the Tupperware. Again. I poked around the sensor connection. Again.

Definition: Stupidity- Doing the same thing over and over expecting different results.

Then I remembered. I am an I&E Technician. I routinely troubleshoot and repair equipment that costs more than my (wife's) house and can affect millions and millions of dollars worth of production. I am supposed to know things.

What is a knock sensor anyway? It senses vibration. It would be called a vibration sensor in an industrial application. In the presence of vibration a millivoltage charge is generated by the sensor. The computer reads that millivoltage signal and interprets the amount of vibration present.

I had already installed two excellent test points at the ECU plug in the form of two butt splices. I connected my meter and started the bike.

I found that both the right and left knock sensors generated about -114.5 millivolts with the bike idling. Both generated about -122 millivolts at 4100 RPM. No appreciable difference between right and left sensor. No spiking, no dropping, no PROBLEMS!

Yet, I am still getting the code. Now, I get it all the time. I check the connectors in the ECU plug. I gently pry (with a fish hook) to get a bit more tension. I am sure there is no problem with the plug.

I cut the wires. Again. I use wire nuts to temporarily switch the left and right wires where they go into the ECU plug. I run the bike.

Still getting the 26 code. If the problem was in the wiring or the sensor, the code would have changed to the Left Knock Sensor, Code 25. But it didn't.

At this point I have determined the ECU is faulty. The PGM-FI is about $825 online.

I'm going to go drink a beer now.
__________________
Never run out of traction, ideas and real estate all at the same time.
Redfish is offline   Reply With Quote
Old September 29th, 2013   #4
BURNOUT
Senior Member
 
BURNOUT's Avatar
 
Join Date: Jul 2011
Location: Syracuse, NY
Posts: 450
Rep Power: 0 BURNOUT can only hope to improve
Default Re: FI Code 26

Hey RED.... Before condemning the $800 ECU, have a look at several other things first. Start at the beginning. Battery fresh with no weak cells? All battery power and ground points clean tight and pasted? Is the ECU getting full power and ground? Have a good look at the ECU power circuit to make sure it's getting full voltage. Same with the ECU ground. Any voltage swings will do weird stuff and lead you down the wrong path. Make sure everything is clean, tight and dielectric pasted. All power points, distribution's and all grounds. Same goes for all connectors, including the ECU plugs. All terminals / plugs, clean tight and pasted?

After all of this is done, then have another run down of the trouble shooting "guide" in the manual. Voltage and resistance values may change.

Another trick I have learned over the years, is to re-set, or "flash" the ECU / ECM. Doesn't matter what kind, make, year, model, gas, diesel, etc. Electronics are electronics. Modules sometimes get confused internally and need a little spanking. Disconnect both battery cables. Let them sit un-connected for around a half hour. Before hooking the battery cables back up to the battery, take the positive cable end and the negative cable end and touch them together for around 10 seconds. Then attach back onto battery properly. This removes all residual voltage in the module. It also wipes out any "learned memory" and resets all internal "switches". You'll then have a clean slate to start with.

I'm also concerned about that one wire that had a 4 ohm reading. Have another look at it.

Good luck!
__________________
Adam
'96 ST1100
STOC #949
Syracuse, NY

BURNOUT is offline   Reply With Quote
Old September 29th, 2013   #5
Redfish
Donators
 
Redfish's Avatar
 
Join Date: Mar 2011
Location: Prairieville, Louisiana
Posts: 2,801
Rep Power: 110 Redfish is a jewel in the roughRedfish is a jewel in the roughRedfish is a jewel in the rough
Default Re: FI Code 26

Good stuff, good points. I do thank you for all your advice. Let me give you some answers so you will know where I am now.

Battery is a couple years old but has excellent voltage. I don't think there are any weak cells. Starter spins as fast as it ever did. (Yes, I am all too familiar with having a weak battery in this ST!) The cables are tight and the connections are clean.

I am somewhat ashamed to say that I have not applied dielectric grease to any of the connections anywhere on this bike. I know, I know. And to think I make my modest living working on electrical/instrumentation problems...

I'll one up your suggestion to "reset" the ECU by disconnecting the battery. I have unplugged the ECU itself several times during the course of this battle. As I type this the accursed thing is sitting unplugged on a bench next to the bike. It makes a decent paperweight.

The wire with the 4 ohm reading was the one I replaced with a completely new wire. All that remains is about 5 inches sticking out of the 26 pin plug at the ECU. I used some special High Temperature wire that is commonly used on boilers and other very hot industrial applications. Unfortunately it is the wrong color but I used what I had available.

Thanks again. You have me thinking about the voltage draining technique you mentioned.

I found Partzilla sells the ECU for $645. Interesting to note that the ECU part # changes and gets cheaper from '08 to present.
__________________
Never run out of traction, ideas and real estate all at the same time.
Redfish is offline   Reply With Quote
Old September 29th, 2013   #6
Mick
Loquacious Member
 
Mick's Avatar
 
Join Date: Oct 2008
Location: Houston, TX
Posts: 623
Rep Power: 116 Mick will become famous soon enough
Default Re: FI Code 26

Quote:
Originally Posted by Redfish View Post
I found Partzilla sells the ECU for $645.
Sorry to hear of your problems Andrew. Any chance you could find a Motorcycle junk yard in N.O. or Baton Rouge that would have a used ECU?
__________________
Mick
Houston, TX ..........STOC# 1134
'16 Versys 650LT, '05 ST1300A(sold), '09 Suzuki Bandit 1250 ABS (sold), '01 ST1100A (sold), '99 ST1100A (sold), '97 ST1100 (sold), '00 VFR (sold), '99 VFR (sold), plus 8 other assorted bikes.

Mick is offline   Reply With Quote
Old September 29th, 2013   #7
chaissos
Donators
 
chaissos's Avatar
 
Join Date: Jun 2012
Location: Rouand'a'bout San Antonio
Posts: 2,082
Rep Power: 85 chaissos will become famous soon enough
Default Re: FI Code 26

If you're sure the ECU is jacked, how about:

03-Up Honda ST1300 Computer CDI ECU ECM Igniter 9725-100126 KEIHIN

http://r.ebay.com/8biBb8
__________________
Scott, 2012 "STutter", STOC# 8642
Go forth and be a force of awesome - do epic shit.
chaissos is offline   Reply With Quote
Old September 29th, 2013   #8
Redfish
Donators
 
Redfish's Avatar
 
Join Date: Mar 2011
Location: Prairieville, Louisiana
Posts: 2,801
Rep Power: 110 Redfish is a jewel in the roughRedfish is a jewel in the roughRedfish is a jewel in the rough
Default Re: FI Code 26

Confused...

The Honda part # for '03-'07 should be 38770-MCS-L01
Edit: My ECU has two #s. The # I listed above and 9725-104020

The ECU # changes from '08 to present and I don't know if they are interchangeable. I have some concern about buying a used ECU. You just never know.

Thank you chaissos. I am considering all options right now. I have to fix it regardless. I cannot sell it or trade it as is. I really want to keep it. For now.
__________________
Never run out of traction, ideas and real estate all at the same time.

Last edited by Redfish; September 29th, 2013 at 02:34 PM.
Redfish is offline   Reply With Quote
Old October 1st, 2013   #9
Redfish
Donators
 
Redfish's Avatar
 
Join Date: Mar 2011
Location: Prairieville, Louisiana
Posts: 2,801
Rep Power: 110 Redfish is a jewel in the roughRedfish is a jewel in the roughRedfish is a jewel in the rough
Default Re: FI Code 26

As an update, I ordered a new ECU from Partzilla. It is supposed to ship tomorrow.

After the suspect ECU sat on the desk next to this computer for a day and a half, I put it back in so I can at least use the bike for transportation. I could ride it to work and back for months and never need to get over 3900 rpm anyway.

So, I rode it for about 15 miles and NO CODE! Then, while passing a slow car, Code! I was actually happy to see that red light come on.
__________________
Never run out of traction, ideas and real estate all at the same time.
Redfish is offline   Reply With Quote
Old October 1st, 2013   #10
Jonjon
Member
 
Jonjon's Avatar
 
Join Date: Jun 2013
Location: Louisiana
Posts: 46
Rep Power: 0 Jonjon can only hope to improve
Default Re: FI Code 26

Sounds like serious frustration, hope the new ECU fixes it for ya. How many miles you got on that 04 ?
Jonjon is offline   Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -7. The time now is 08:34 PM.


Powered by vBulletin® Version 3.7.2
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Copyright 2004-2011 ST1300.US.COM