FI light came on

While on a short ride, I notice the FI light was on while on the highway going around 70. I pulled off near home and stopped to get gas. After restarting the bike, the FI light does not come on again. At home the FI appears to show normal condition. It lights up for a couple of seconds when the engine switch is turned to run, then it stays off. It did not blink at anytime.

Should I be concerned?

Thanks
JC

You may have a beginnings of a knock sensor wiring problem or an ECM failure. The former is much more common and is easy and inexpensive to fix.

Check the ECM for stored codes and let us know if you find anything. If not, it's nothing that will leave you stranded, but keep an eye on it. See if you can induce the problem by riding continuously at above 4,000 RPM, because that's where the ECM tends to complain about it.

--Mark

Get it above 3900 RPM for at least 10 seconds. This can be done in neutral on the side or center stand. See if the the FI light comes on. Do NOT kill the bike. With the bike in neutral, engine running put the side stand down. (If it isn't already). Count the flashes of the FI light taking note of "long" and "short" flashes. A long flash counts as 10, a short flash counts as 1. If you get code 25 or 26 that is a knock sensor.

There are some excellent threads in this section concerning that issue.

My bet would be some debris was clogging the 5way t on the starter valves. Easy to remedy without buying sensors and such that were probably not needed. Start checking the simple and free stuff first. .02

Igofar said:

My bet would be some debris was clogging the 5way t on the starter valves. Easy to remedy without buying sensors and such that were probably not needed. Start checking the simple and free stuff first. .02

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Will pluggage in the 5 way T affect the bike at 70mph? I was under the impression that was associated with idle speed issues. I honestly don't know one way or the other.

I 100% agree on checking simple and free first. Since 70 mph was mentioned and that corresponds pretty well with codes 25 and 26 I figured it was both simple and free to run it to 3900 rpm for 10 seconds. Of course, the gas to do so won't be free...

Redfish said:

Of course, the gas to do so won't be free...

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Almost free - maybe 0.02 worth if tested while parked...

Redfish said:

With the bike in neutral, engine running put the side stand down. (If it isn't already). Count the flashes of the FI light taking note of "long" and "short" .

Click to expand...

I also found you can do this while riding. Shift into neutral and use your foot to lower the centerstand.

There is another active thread about bikes popping the FI light when the bike is held above 5200 rpm for 20-25 seconds.

T_C said:

I also found you can do this while riding. Shift into neutral and use your foot to lower the side stand.

There is another active thread about bikes popping the FI light when the bike is held above 5200 rpm for 20-25 seconds.

Click to expand...

Fixed it for ya. Might be a little tough to lower centerstand while riding.
What is the title of the other thread you referred to?
edit: never mind, I found it.

Sorry for the delay in getting back to this. I finally was able to read the code, which I believe is 26. After tearing down more plastics than I ever did, I've testing for short circuit and continuity to the ECM on both sides (R/L) and the wiring is good. Based on the manual, the only thing left is the knock sensor itself. Can someone confirm that somewhere in the forum someone suggested the manual is wrong in terms of left side vs right side knock sensor? Because the color of the wiring is flipped in the manual vs what is on my bike (2004 ST1300). With the code at 26, would that be the right side like the manual says?

Before I plunk down $75 or $150 for 2 knock sensors, does anyone have a suggestion on something else to try?

Thanks
JC

fnmag said:

Try post #4.

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Another weekend project...

Took a couple of hours to finally get the 5 way tree out. It is very clean. Look down the vacuum tube as far as I can and it's clean too. So it looks like it's the knock sensors.

Is there a test for the knock sensor? Or just have to replace them?

JC

There is no check/test procedure for the knock sensors in the service manual, but you may want to try this check described by Redfish to check the voltage output from the sensors before you run out to buy a new pair of sensors: https://www.st-owners.com/forums/showthread.php?132408-FI-Code-26
I'm not real sure how you would connect a multimeter to check the voltage without cutting and splicing any wires as Redfish had done, but there may be a way to clip a test lead directly to the connector on each sensor. I assume you will be looking for voltage between that point and ground, since there is just one wire connected to the sensor. Look for ~114mv at idle and 122mv at 4100rpm. If you want any additional info on this, you may want to reply to the above thread and/or pm Redfish. My understanding is that these sensors very seldom fail. From the posts I've read failure of the ECU is more common, unfortunately. Hope this helps,

Don

If your wiring is good, it is not the knock sensors, but the ECM/ECU. I've had this and so have many others. You can probably find one from a wrecked parts bike on ebay, usually for about $150 or so. Much better than the $1000+ that the dealer will charge you. Just make sure you get the right one. The ECM was changed in 2007? Also be careful that some sellers will call the ABS control unit a ECM. Make sure you get the right part.

Don B said:

There is no check/test procedure for the knock sensors in the service manual, but you may want to try this check described by Redfish to check the voltage output from the sensors before you run out to buy a new pair of sensors: https://www.st-owners.com/forums/showthread.php?132408-FI-Code-26....

Click to expand...

I read through almost the entire post. I will do some more test with the knock sensors before buying anything. The last thing I want to do is buying something I don't need. The next to the last thing I want to do is buying an ECU.

Bummer, it looks like the problem with the code 25 is a faulty ECU, as many have indicated. I cross wired the two knock sensors and was still getting code 25. I did it twice just to make sure the wires I put in have good continuity. Then I removed the wires and plug the wires into the correct sensors, and received code 25 again.

I do know someone local with a '06, maybe if I offer a beer or 2, I can borrow his just to make sure it's the ECU. There are currently no suitable ECU on eBay that I can find for a 04' ST1300 Non-ABS. Since my bike is parked to the winter, I can take sometime locating one.

I'm not sure if the ECU is any different on the ABS vs. non-ABS versions since there is a separate control module for the ABS system.

Don B said:

I'm not sure if the ECU is any different on the ABS vs. non-ABS versions since there is a separate control module for the ABS system.

Click to expand...

You are correct that ABS and non-ABS uses the same ECU or ECM, at least for an '04 ST. I didn't check the other years...

The friend who I was trying to borrow the ECM from mentioned he is on his second ECM and is reluctant to lend out such an expensive part. I don't blame him one bit. I would be reluctant as well.

After searching high and low, I ended up purchasing a new one from Partzilla, received it yesterday and installed today. It seemed to have solved the problem. I brought the rpm to ~4500 for over 20 secs multiple times and did not get the FI light. I did verified I was still getting the FI code before the swap. It is unfortunate to have this problem occur on such an expensive part and even more so to a part where the only option is to replace it.

I did contemplated about getting an used one through eBay or salvage yard. First, there were none to be had. Second, the chance of getting a faulty one is ever present. In the end, I decided this will to be my Xmas present to myself...

Wow what a pain in the rear to get this problem solved, glad it looks like it is repaired.