F1 light

The local dealership, and listening to the advice of folks on a "forum", rather than using the correct diagnostic codes.
The dealership's diagnostic codes also wanted to replace the map sensor switch, fuel injectors, and the ECU :rofl1:
We are all on the same page, and in agreement with trouble shooting by following the codes, all I am trying to point out is they can be misunderstood sometimes (map sensor switch/goop in lines causing the map sensor switch code) etc.
 
Okay so I went to the dealer and said how much to order a knock sensor. OUCH. Guess Tupperware coming off to look for bad connections. I am assuming that the 5 way T being discussed is under the air cleaner box hooking to each throttle body. Is it accessed from the sides or does the whole air cleaner box need to be removed?
 
Honda does think alot of their knock sensors huh?
The 5-way tee rests inside the throttle bodies. You simply remove the air box cover, snorkels, bases, and the air box base assembly. Search the forum articles for more information on it.
If you would like to talk on the white courtesy phone, PM me a number and I'll call you tomorrow and explain in detail how to do it.
Igofar
 
okiehick82 said:
Okay so I went to the dealer and said how much to order a knock sensor. OUCH. Guess Tupperware coming off to look for bad connections. I am assuming that the 5 way T being discussed is under the air cleaner box hooking to each throttle body. Is it accessed from the sides or does the whole air cleaner box need to be removed?
Click to expand...

Here is a pix of a melted sensor.

What does yours look like?
 
I went through this same error code (right knock sensor). Here's what I did to identify my problem. 1) I checked the wiring from the sensor all the way to the ECM and found no problems 2) I swapped the knock sensors from one side to the other. If the error was truly a knock sensor, the fault should have followed the sensor, right? It didn't follow the sensor, I still got FI-26... that ruled out the knock sensor being bad. 3) I cleaned the 5 way T... in fact I replaced it and all the hoses associated with it, but the FI-26 error still showed up. 4) This pretty much eliminated everything but the ECM. I just about stroked out when I found that the replacement part was north of $700 new. I managed to find one on eBay for $75 that came off a wrecked 2006 (my bike is also a 2003) that only had 10,000 miles on it. I took a chance and went with the eBay ECM and that resolved the issue. Keep in mind that Honda made a change in the ECM in model year 2008 to a different part number that won't work on an 03. The correct part number is 38770-MCS-L01.

If you can find another owner of an 03-07 ST in your area, perhaps they might let you swap in their ECM into your bike to see if this clears your problem... unfortunately I could not find another ST in my area to check if my unit was defective, hence I purchased the cheapie off eBay. Good luck with finding your problem, because when the error shows up, the ignition timing is retarded and gas mileage and performance degrades.
 
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okiehick82 said:
Okay so I went to the dealer and said how much to order a knock sensor. OUCH. Guess Tupperware coming off to look for bad connections. I am assuming that the 5 way T being discussed is under the air cleaner box hooking to each throttle body. Is it accessed from the sides or does the whole air cleaner box need to be removed?
Click to expand...

I respectfully suggest you resolve the knock sensor problem first before you worry about the 5 way T or starter valve sync. There may be nothing to be gained by doing the latter, and that won't resolve the FI light issue. Ref post #18.
 
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Don B said:
What you're looking at is a melted connector. Ref the post that the thumbnails came from.
Click to expand...

Thanks for the pictures. I recently had the left side Tupperware off. I wasn't looking for knock sensor problems at the time so didn't even glance at it. Guess it is coming back off so I can look at the connection and the sensor. Perhaps I can figure out something with my meter. If not I will swap side to see if the fault swaps sides.
 
You don't have to remove the tupperware to see the knock sensor(s). Simply remove the lower black cowls on both sides, then lay down next to the bike and you can see them.
 
Igofar said:
You don't have to remove the tupperware to see the knock sensor(s). Simply remove the lower black cowls on both sides, then lay down next to the bike and you can see them.
Click to expand...

Thanks for the information. I am not fond of removing the Tupperware.
 
Igofar said:
You don't have to remove the tupperware to see the knock sensor(s). Simply remove the lower black cowls on both sides, then lay down next to the bike and you can see them.
Click to expand...

Removed the left lower cowl looked in from the bottom. I see nothing that looks amiss. Plug feels firmly attached. Nothing looks like it has gotten hot or melted. Only thing I could see that might be of concern was there appeared to be some green coloring were the wire went into the connector. Might indicate some corrosion at the end of the wire where it connects to the plug. Thanks for the tip on how to check it without stripping the bike.
 
Check the one on the right side of the bike, and also the neutral wire switch (new oil level view window) These are the two areas I commonly find stuff melted.
Igofar
 
Igofar said:
Check the one on the right side of the bike, and also the neutral wire switch (new oil level view window) These are the two areas I commonly find stuff melted.
Igofar
Click to expand...

I have have done a little more research before removing the Tupperware. As you suggested I removed the lower black cowl to examine the knock sensor. I couldn't see any problems. What I have noticed is that it seems to be outside tempature related. Last night with the out side tempature at about 65 degrees I tried to get the fault to kick on and couldn't. I tried pretty hard. Not sure I if this is an indication of the issue I am trying to chase down but thought I would throw out all I had found out.
 
okiehick82 said:
What I have noticed is that it seems to be outside tempature related. Last night with the out side tempature at about 65 degrees I tried to get the fault to kick on and couldn't. I tried pretty hard. Not sure I if this is an indication of the issue I am trying to chase down but thought I would throw out all I had found out.
Click to expand...

This is kind of what my bike would do... the fault was intermittent. I replaced the ECM and the fault went away.
 
mageerc said:
This is kind of what my bike would do... the fault was intermittent. I replaced the ECM and the fault went away.
Click to expand...

So the next day I went out to run errands with the temp indicated as 77. The weather is beautiful I am feeling good and I got the F1 light 3 times in 5 miles of town riding. Only did 4 or 5 wheelies and never went above 85 mph. Each time the light came on I would grab the clutch turn the key off then let the clutch out to refire the bike. The F1 light would go away. On the way home it was 79 degrees I roder harder and could not get the F1 light to come on. Now I am baffled.
 
Qomar said:
Usually the problem is with the knock sensor either on the left or right. I have been discus about this thing with some friend and they told the real problem is with the CCU. Mine ST 04 facing the same problem but I just ignore it coz it is so expensive to but a new CCU
Click to expand...

How long have you been riding with this issue? And have you noticed any changes?
 
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