ABS series 1 ECU what's inside?

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Knowingly I purchased a bad ABS bike. Let's not say 'bad', just non-ABS, to save her feelings. And, I'm perfectly happy (having owned an ABS ST model previously) riding around on a 'non'.

Reading up on the threads, they seem to hit a wall when opening the ABS electronic control unit and finding it 'potted' with goo. I inherited a second 'bad' spare unit that blows the ABS fuse when installed, so I opened it to see what there was to see. Yes it's 'potted' aka sealed, but not with epoxy as mentioned on a prior post. It's floated full of black silicon just like caulking.

******** Here's my single contribution ***** The case can be opened, and the circuit board can stripped of the silicon material. I found online that there are silicon stripping agents for just this electronic purpose, Dynasolve (218, 220, 225, and 230) is one example. Even WD-40 will take 'some' of it off, but that's not the best choice.

This is where I'll stop, just when it's getting good. Why? Ambition is one thing, but my limited abilities are another. Even if I got the PCB (printed circuit board) de-siliconed and pristine. . . I don't have anywhere to go after that, without a schematic and with my limited tools.

Here's where you can take over, if there's someone out there with those abilities. Hope this Dynasolve tip, and the encouragement that one can strip back to the PCB board will encourage further discovery.
 

Blrfl

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Understanding how the innards are wired up is going to be of limited use when the special sauce is in the software. Extracting and reverse engineering that is a significant job and might be impossible if it's stored on the CPU and the fuses that make it readable externally have been blown. (Yes, that's a thing.)

--Mark
 

SupraSabre

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Just remember that there is a difference between the '02-'07 & the '08 & on!

Just in case you're thinking of replacing one! :D
 

paulcb

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Should we assume this is an ST1100?
 
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If you're trying to find the cause of the electrical short that blows the fuse and fix that issue, then that might be possible. Trying to reverse engineer the ABS software on a faulty ABS unit isn't going to be possible, I agree with Mark on that one. It wasn't clear from your post exactly which of those two problems you are currently trying to solve by stripping off the silicone, but your mention of a schematic suggests you are considering its possible to repair the faulty ABS logic somehow. Stop now, you're wasting your time.
 

Blrfl

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...although it might be worthwhile to reverse engineer the bit of circuit that listens to the knock sensors in the 1300's ECM, because that bit's probably easily repaired.

--Mark
 
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Believe it or not, it's usually easy to fix something that is blowing fuses. The problem is usually a bad filter cap in the power supply or if it's powered by AC, either the cap or a bad rectifier. I just fixed a friend's microwave oven that was blowing the 18 Amp line fuse. It turned out to be a shorted HV power supply filter cap.

But if a ABS computer is blowing fuses, it could be caused by a shorted ABS device the ABS computer is connected to ( control valve ? ) . But that would be easy to determine - just Ohm out the input to the device the ABS computer is connected to. My guess is that the computer drives a solenoid in the control valve. A solenoid has a pretty low resistance, so you would have to compare your reading with a reading from a good control valve.
 

wjbertrand

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I'm here to tell you Honda's ECM, weather the "E" stands for engine or electronic, are true black boxes of mystery. Nobody stateside understands them and the standard repair is to replace, not diagnose, them.
 

Nashcat

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There is a company that can reflash the ECM on Goldwings. There were people getting it done to fix a low speed stumble.

John
 
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But if a ABS computer is blowing fuses, it could be caused by a shorted ABS device the ABS computer is connected to ( control valve ? ) . But that would be easy to determine - just Ohm out the input to the device the ABS computer is connected to. My guess is that the computer drives a solenoid in the control valve. A solenoid has a pretty low resistance, so you would have to compare your reading with a reading from a good control valve.
+1 most likely a shorted hold or dump solenoid in either the front or rear module.
 

Blrfl

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(I moved this to the 1100 area since Robin has an 1100.)

...I inherited a second 'bad' spare unit that blows the ABS fuse when installed...
I just noticed this. There isn't the ABS fuse, there are three or four depending on your bike's model year.

One of the things the system does on power-up is exercise all of the mechanical parts to make sure they work. If you're not blowing the fuse that feeds the ABS unit, your "bad" spare (the one you tore apart) is actually just fine and there's a short somewhere else in the system.

--Mark
 
OP
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Hi Mark:

Thanks for your input. Right you are about the ABS sub-panel of fuses behind the battery. I've 3-ECU's (that came with the bike). Two don't blow any fuses in that 3-fuse block. As you noted, the one I opened up does flow the (10 amp fuse. . . not pumps). Why I mentioned it, there may be a small simple defect feeding the ECU (like a voltage regulator, capacitor, or other large component) on that non-user-servicable board. . . you guessed it, that could be user serviced.

I'm amused at some of the responses I've gotten. Some folks are can-do, others are 'realists' aka defeatists who won't even try to figure it out and work to convince others not to even try.

However; yesterday I rode the bike for the first time and had a blast! Think I'll just enjoy it as a non-ABS version for a while. Later I may get an ECU, or trade up to one with a working ABS. Time'll tell.

Thanks for your input.

Robin
 
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