ECM - repair / rebuild ????

JeffreyJ

JeffreyJ

Joined
Oct 4, 2009
Messages
20
Location
Orlando, Florida
Bike
08 GL / 04 ST
My 04 with 52,000 miles started flashing code 26 (right side knock sensor). I swapped the left sensor with the right and the code remained 26. Continuity was good and the wire to the ECM was not shorted. I swapped the ECM with a friend and voila - no code 26. All is well. Now the question is - where do I find someone to repair the ECM? Is there a source for refurbished ECMs? I have of course will check around in junk yards but I wonder if anyone repairs them. I know there are companies who either make or refurbish for the Honda car. Any thoughts?
 
Before you haul off and replace the ECM, you should know that the manual has codes 25 and 26 backwards. 26 is actually the left one.

When you swapped in the other ECM, did you ride the bike for awhile with it in there or just power it up? Did the 26 return after you swapped the original ECM back in? (I'm thinking maybe you just had a contact problem and cycling the connectors a couple of times solved it.

--Mark
 
Blrfl said:
Before you haul off and replace the ECM, you should know that the manual has codes 25 and 26 backwards. 26 is actually the left one.

When you swapped in the other ECM, did you ride the bike for awhile with it in there or just power it up? Did the 26 return after you swapped the original ECM back in? (I'm thinking maybe you just had a contact problem and cycling the connectors a couple of times solved it.

--Mark
Click to expand...
Thanks for your response. Regardless of codes being backwards, if indeed the sensor was bad, the code should have changed from 26 to 25.

I now have over 250 miles with the borrowd ECM and all is well. Now my friend has code 26 on his ST.
 
Sounds like a confirmation to me. Can't help you with rebuilds/refurbs.

--Mark
 
I would check the knock sensor sub harness very carefully. I had the same thing happen to my 04 replaced the ECM and all was well for a few months then it started again this time the harness was bad enough that when we moved it would short out had to replace the harness.
ken
 
unchargedken said:
I would check the knock sensor sub harness very carefully. I had the same thing happen to my 04 replaced the ECM and all was well for a few months then it started again this time the harness was bad enough that when we moved it would short out had to replace the harness.
ken
Click to expand...

I was prepared to rewire the knock sensor with wire with high temperature insulation....I still have the wire. It should be pretty simple to cut the existing wire at the sensor and feed it along side the harness to the ECM connection. If that was the case I would have done both the right and the left.....alas, my problem is fixed. I saw the ECM on Ebay. I will be looking for a crashed ST in Florida. Used ECM should be less than $100.00.
 
I'm wondering now that you may have "corrected" the issue, but the code is still stored in the ECM until it is cleared..... not familiar with the procedure to erase codes for this or if the dealer's diagnostic tool is required..... then, if erased, does it return on the non-offending bike?
 
RaYzerman said:
I'm wondering now that you may have "corrected" the issue, but the code is still stored in the ECM until it is cleared..... not familiar with the procedure to erase codes for this or if the dealer's diagnostic tool is required..... then, if erased, does it return on the non-offending bike?
Click to expand...
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1. Erasing the ECM memory is easy. Paper clip shorting of two contacts - did that several times before I took the ECM off as I thought that switching sensors will solve the problem.

2. Since the problem was with the ECM itself, not the wiring or the sensor, the problem remains within the ECM !!!!!!!!!!!!!!!!!! This is not a virus. It appears that the ECM was issuing a false warning because of an internal software or firmware issue. The ECM has several integrated circuits and logic chips, a bunch of resistors and capacitors and one or two of them is misbehaving.

I spoke to people who rebuild Honda vehicle ECM's and they DO NOT do motorcycles. I will be sourcing one out of the wrecked ST. If anyone knows a totaled ST let me know.
 
Check the connector pins that connect to the knock sensors on the ecm.
You may just have a bad solder joint that needs to be reflowed.
 
st1300r said:
Check the connector pins that connect to the knock sensors on the ecm.
You may just have a bad solder joint that needs to be reflowed.
Click to expand...
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That was the first thing I checked - continuity and short to ground. If that was a problem swapping the ECM would not have solved the problem.

I got my hands on a good used one for $80.00.
 
So now...rip into the bad one and fix it. :) Let us know how that goes and what you did. Nothing like having someone elses ECM around to be the test victim. :D
 
JeffreyJ said:
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That was the first thing I checked - continuity and short to ground. If that was a problem swapping the ECM would not have solved the problem.

I got my hands on a good used one for $80.00.
Click to expand...

Just wanted to commend you on your troubleshooting logic and soon to be completed fix. If I ever move to the 1300, you're the one I'll be asking.
 
JeffreyJ said:
=============================================
That was the first thing I checked - continuity and short to ground. If that was a problem swapping the ECM would not have solved the problem.

I got my hands on a good used one for $80.00.
Click to expand...

The solder connections inside the ECM. 80 beans ain't too bad.
Glad you got it sorted out.
 
st1300r said:
The solder connections inside the ECM. 80 beans ain't too bad.
Glad you got it sorted out.
Click to expand...

I may very well pop that sucker open to check the pin solder on the inside. Beyond that, if it is indeed an IC problem, well....I will bend over and kiss my heinee goodbye. Personally, I suspect it is more than a bad solder. I wish there was a bench test for it.

I called several companies that advertise ECM rebuild, recondition and bench test....but only for cars. No doubt these things are very very specific.

I am also surprised that there is no high performance after market replacement product.
 
If it isn't too much trouble, clear, high-res pictures of both sides of the board would be appreciated.

JeffreyJ said:
I am also surprised that there is no high performance after market replacement product.
Click to expand...

The ST isn't a big enough seller to make developing one worth the expense.

--Mark
 
It's an outside chance but a high res photo of the board top and bottom might turn up some programming clues unless they're custom chips or blacked out.
 
I doubt pictures will give any hints about how it functions; I'm just curious about the major components.

--Mark
 
Blrfl said:
I doubt pictures will give any hints about how it functions; I'm just curious about the major components.

--Mark
Click to expand...

Truth be told, the weather here is F A N T A S T I C and I am going riding. The bike runs like a dream, the FI light is out and the temperatures are hovering around 72 daygrease, humidity is low.......some people are gone fishing - I am going RIDING. You blame me? Will keep you posted if and when I crack that sucker open.

Ta Ta fer now.
 
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