Ignition coils

FinalImpact

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EDIT--ADDED A STEP:-->
- Key on, coils connected, confirm BATTERY voltage at red wires to both coils. Use Battery Ground for (-) lead, (+) lead to coils. TELL US THE VOLTAGE!
- Key on, coils connected, measure BATTERY voltage at the Orange and Grey Wires. Battery is (-) lead or meter ground. TELL US THE VOLTAGE!
- Key off, ECU connected, Orange & Grey coil wires disconnected from coils, OHM between chassis ground (batt Neg term) and Orange and then chassis ground and red. Tell us the values. Reading in Ohms!
- Key off, ECU disconnected, OHM from Orange and Grey back to ECUs wire connector. Both colors should read the same. Tell us the values.

Off hand sounds like this fried your ECU. That will help point fingers at the fault condition.

Ohms - tell us the options on your meter (pictures are easy).
- If the Ohms setting is intimidating, this is the basic concept:
Probes in the air in Ohms mode will show infinite resistance. Current can not conduct between the probes in the air, thus resistance value is very large.
Probes touching each other "shorted" should read less than 0.50 Ohms or a dead short. This shows electricity (current) could flow. Touching these same probes to a known good wire at each end should show a value less than 2.0 Ohms.

Thats it. Let us know.
 

TheFemaleBiker

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So I have narrowed it down to the ECU being the problem. The wire from the coil to the ECU shows between 0-2ohms of resistance which in my understanding means that the wire is fine. I inspected the outside of the wiring too, no rubbing marks or breaks anywhere. I then did a voltage drop test on the wire (coil side) when starting/running the bike and the results were that it just stays at a constant 12v and does not change whereas the other coil does, it drops between 12v+ and then -12v. I did also test it from the ECU side too, had the same results. My battery was showing 11.54v which is understandable as it's been sitting there not running for about 3/4 weeks, It does still start the bike on the two cylinders :) I also tried putting a fully charged battery in just to try it and rule out any other problems, that didn't fix anything.

I am going to break into my ECU sometime this week and have a nosey, I need a new one anyway so i'm not loosing anything if I can't fix my current one myself. Any suggestions on how to open up the ECU without too much damage?

(apologies it took me a while to reply, been rather busy with work and other things at the moment)
 

FinalImpact

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Just to be certain, remove battery power, unplug the ecu, unplug the coil, connect one probe lead to engine ground chassis (battery "-" lead), connect the other to the free coil wire, not the red set. Verify Ohms reads high like infinite or > 1meg ohm.

This would support the ecu being bad.
If it reads low, like 1ohm or less, its the wire harness.
 

TheFemaleBiker

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Just to be certain, remove battery power, unplug the ecu, unplug the coil, connect one probe lead to engine ground chassis (battery "-" lead), connect the other to the free coil wire, not the red set. Verify Ohms reads high like infinite or > 1meg ohm.

This would support the ecu being bad.
If it reads low, like 1ohm or less, its the wire harness.

But I have already checked that wiring by disconnecting the wire from both the coil and ECU and checking the resistance which showed 0-2ohms which means it completes a circuit etc, so it's not the wire. I don't understand how testing that wire again but in a different way would change the outcome? :confused:
 

FinalImpact

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But I have already checked that wiring by disconnecting the wire from both the coil and ECU and checking the resistance which showed 0-2ohms which means it completes a circuit etc, so it's not the wire. I don't understand how testing that wire again but in a different way would change the outcome? :confused:


Because this tells us beyond a doubt that the wirs is not shorted to the chassis/ground.

The wire **could** test fine from end to end which it does. But that doesn't mean its not also shorted to chassis ground.

This is a must do test especially if the ecu can not be returned.
 

Motogiro

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I think the thought is that if the wire is staying at positive 12 vdc and not dropping in voltage that the wire is not seeing ground potential. Never hurts to check though because there may be something we're not seeing. Another test could be to remove the wire to the ECU and ground it intermittently and see if you get a spark off the secondary coil output. This will prove the line is operating.

We did have a member who lost the pin on the ECU for a coil to corrosion. I don't remember for sure but I think they repaired it by fashioning a new post for it. If it was a corroded pin I would try my best to buss that line out of the ECU and attach it to the coil control.

Here's an interesting thought and who knows that the ECU doesn't in fact fire the coils this way. One coil is always firing 180 degrees from the other so could we use the coil control signal that is working coil control to switch the coil on the dead side? Why not? If you had a switching transistor set up that conducted when the working coil control was at a high or positive. This would fire the non working coil 180 degrees out! That's how it normally fires... :) I think I figured it out one day that you need switching of upwards 7Mhz or better. I think Randy and I were discussing this a while back for a coil over control.... :) If it would cost $500 for a new ECU I'd be on it like a duck on a June bug! So you wouldn't be switching any significant additional current load on the working line. This could be a work around?
 

FinalImpact

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I think the thought is that if the wire is staying at positive 12 vdc and not dropping in voltage that the wire is not seeing ground potential. Never hurts to check though because there may be something we're not seeing. Another test could be to remove the wire to the ECU and ground it intermittently and see if you get a spark off the secondary coil output. This will prove the line is operating.

We did have a member who lost the pin on the ECU for a coil to corrosion. I don't remember for sure but I think they repaired it by fashioning a new post for it. If it was a corroded pin I would try my best to buss that line out of the ECU and attach it to the coil control.

Here's an interesting thought and who knows that the ECU doesn't in fact fire the coils this way. One coil is always firing 180 degrees from the other so could we use the coil control signal that is working coil control to switch the coil on the dead side? Why not? If you had a switching transistor set up that conducted when the working coil control was at a high or positive. This would fire the non working coil 180 degrees out! That's how it normally fires... :) I think I figured it out one day that you need switching of upwards 7Mhz or better. I think Randy and I were discussing this a while back for a coil over control.... :) If it would cost $500 for a new ECU I'd be on it like a duck on a June bug! So you wouldn't be switching any significant additional current load on the working line. This could be a work around?

True... ^^^ bold.

Would be nice to know WHO failed first. Likely pointing at the ECU but could have been the coil had a primary short?? IDK...
If it were state side id offer to inspect the ecu... But not worth shipping.

Somehow i think switching is more complex, as idle time would have huge dwell and saturation values if one triggered the other. I'd guess a timing component is involved in each leg to prevent over saturation of the coil at lower rpms... Just a thought...

And IF the ECU was the first too go, im not sure id trust the other half....

As for being creative, out of reach for me... Even tho id almost bought the valve cover and stick coils... But im still tinkering....
 
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Motogiro

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True... ^^^ bold.

Would be nice to know WHO failed first. Likely pointing at the ECU but could have been the coil had a primary short?? IDK...
If it were state side id offer to inspect the ecu... But not worth shipping.

Somehow i think switching is more complex, as idle time would have huge dwell and saturation values if one triggered the other. I'd guess a timing component is involved in each leg to prevent over saturation of the coil at lower rpms... Just a thought...

And IF the ECU was the first too go, im not sure id trust the other half....

As for being creative, out of reach for me... Even tho id almost bought the valve cover and stick coils... But im still tinkering....

I did think of the dwell and that would be the major problem. The heat and saturation would definitely be an equation from on time of the coil. I think field collapse would work timing wise but I agree saturation is a problem. Would be interesting to see the switching on the O scope. :)

Looking at the coil from the OP's coil failure almost looks like there was an over heating, sequential internal expansion and then....
 

FinalImpact

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<< SNIP >>

I am going to break into my ECU sometime this week and have a nosey, I need a new one anyway so i'm not loosing anything if I can't fix my current one myself. Any suggestions on how to open up the ECU without too much damage?


Because of the of vibes, heat and moisture, one can anticipate its potted in some form of evil impenetrable resin like substance.

With its polymer like case, I've had good luck with a belt sander or a high speed sanding disc to get through the case. If its fully potted, think pouring epoxy resin all over a circuit board, its pretty much pointless task.

That said, they typically don't pot devices under heavy load (sources of heat) like the coil drivers for both ignition and injection so you may find an empty cavity with "conformal coating,." Its a Thin clear vapor and vibration barrier, which is no fun to work with but, they make solvents for it also. PS - some do peel up with heat as it releases trapped solvent making it soft. So you might try that too once the case is removed. GOOD LUCK! Picture Plz!

Typically things the protect public safety (think banking encryption devices) always get potted in black. It resists most chemicals.
 

TheFemaleBiker

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Right, I am going to have another nosey at it tomorrow if I can (depends what the weather decides to do) I'll test the wire again just to be double sure. And see what the outcome is.

I did notice the other day when poking around that I can pull the ground wire out very easily coming from the plug going into the ECU, so maybe that could be an issue? Although I don't think it would be as surely there would be other problems with other components if that was an issue? :confused:

If it turns out to be the ECU then I will try and crack it open and have a nosey at it. And of course I will post some pictures if I can get into it.

I'm starting to get quite sad about this whole thing as I haven't been able to ride my own bike for well over a month now, makes me just want to send it to a garage and get it fixed by them, but I'd end up paying an absolute fortune for it all. :(
 

Motogiro

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Right, I am going to have another nosey at it tomorrow if I can (depends what the weather decides to do) I'll test the wire again just to be double sure. And see what the outcome is.

I did notice the other day when poking around that I can pull the ground wire out very easily coming from the plug going into the ECU, so maybe that could be an issue? Although I don't think it would be as surely there would be other problems with other components if that was an issue? :confused:

If it turns out to be the ECU then I will try and crack it open and have a nosey at it. And of course I will post some pictures if I can get into it.

I'm starting to get quite sad about this whole thing as I haven't been able to ride my own bike for well over a month now, makes me just want to send it to a garage and get it fixed by them, but I'd end up paying an absolute fortune for it all. :(

I also just realized you may have to get a replacement ECU paired to your immobilizer. How will that work? We don't have to deal with that on the US bikes but you're in EU. Do you have to take it to someone who tells the immobilizer and ECU to make friends?
 

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I also just realized you may have to get a replacement ECU paired to your immobilizer. How will that work? We don't have to deal with that on the US bikes but you're in EU. Do you have to take it to someone who tells the immobilizer and ECU to make friends?

When the motorcycle is first purchased, the ECU on the bike is in “a virgin state “. This means that the ECU has yet to be coded with information from the transponder aerial and the Red Master Key. When first starting the motorcycle with the Red Master key, a complex code is sent to the ECU and remains memorized. This ECU is then synchronised with the master key and transponder aerial (the immobiliser system). It can then only be used with that particular motorcycle and immobiliser system. It cannot be used on any other motorcycle.

I have my red master key and have found a place that can supply a second hand virgin state ECU (they somehow reset it) but it's a case of waiting unti they get my specific model ecu in stock (4S8) from their suppliers (motorcycle breakers) which might be some time.

The other way of doing it would be to get a new ecu, along with a new transponder aerial (ignition barrel) and new set of keys that are already coded to each other but that's more expensive as you can imagine.
 
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Motogiro

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When the motorcycle is first purchased, the ECU on the bike is in “a virgin state “. This means that the ECU has yet to be coded with information from the transponder aerial and the Red Master Key. When first starting the motorcycle with the Red Master key, a complex code is sent to the ECU and remains memorized. This ECU is then synchronised with the master key and transponder aerial (the immobiliser system). It can then only be used with that particular motorcycle and immobiliser system. It cannot be used on any other motorcycle.

I have my red master key and have found a place that can supply a second hand virgin state ECU (they somehow reset it) but it's a case of waiting unti they get my specific model ecu in stock (4S8) from their suppliers (motorcycle breakers) which might be some time.

The other way of doing it would be to get a new ecu, along with a new transponder aerial (ignition barrel) and new set of keys that are already coded to each other but that's more expensive as you can imagine.

Thank you for the info on this as I was unfamiliar of the process. :)

Good luck with the procurement of a replacement ECU!
 

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FinalImpact

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If your source de-registers the previous ignition switch key pairing to the ECU, you are good to go. Even at that, I think with the RED key you can simply pair it following the OEM info... FWIW the info is there and you might take a peak if you don't have it already. Search FZ6 Muffler Bearing section 8 - 63 comes to mind. yep!

To register a code re-registering key:
1. Turn the main switch to “ON” with the code re-registering key.
NOTE:
Check that the immobilizer system indicator light comes on for one second, then goes off. When the immobilizer system indicator light goes off, the code re-registering key has been registered.
2. Check that the engine can be started.
3. Register the standard key, following the instructions in the section below. 8-63.... follow through.
F/I
 

fazil

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There is only the FZ6 5VX model Ecu on there, mine is the 4S8 model

5VX is for S1 model and 4S8 is for S2 version.
I think they can fit each other except for the manifold air sensor.
 

Motogiro

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5VX is for S1 model and 4S8 is for S2 version.
I think they can fit each other except for the manifold air sensor.

Does that mean either the 5VX or 4S8 prefix ECUs are compatible with US bikes?
Here are US ECU numbers:

S-2: Engine Control Unit Assy XC 4S89 CA
4S8-8591A-20-00

S-2:
Engine Control Unit Assy CA (5VXJ)
5VX-8591A-20-00

These are CA bike specs.

I would imagine EU bikes with immobilizer are going to have a different P/N?
 

TownsendsFJR1300

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Does that mean either the 5VX or 4S8 prefix ECUs are compatible with US bikes?
Here are US ECU numbers:

S-2: Engine Control Unit Assy XC 4S89 CA
4S8-8591A-20-00

S-2:
Engine Control Unit Assy CA (5VXJ)
5VX-8591A-20-00

These are CA bike specs.

I would imagine EU bikes with immobilizer are going to have a different P/N?

I would think (and could be wrong) that with all the ECU's they repair, they could repair the Ops. Yes, it costs slightly more than a used one BUT you know its going to work AND you don't potentially have to change all the lock cylinders (seat, gas cap, helmet lock, etc).

Caveat; that's if its necessary with a used ECU, maybe new RED main key, etc..
 

Motogiro

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I would think (and could be wrong) that with all the ECU's they repair, they could repair the Ops. Yes, it costs slightly more than a used one BUT you know its going to work AND you don't potentially have to change all the lock cylinders (seat, gas cap, helmet lock, etc).

Caveat; that's if its necessary with a used ECU, maybe new RED main key, etc..

For repair I think the main concern will be whether the unit is potted being it may be a component failure. If it's potted the potting would need to be somehow emulsified or maybe the slave transistors are accessible for the very reason on repair.

I didn't think about all those other locks that are keyed alike so, yeah, repair would be a win win! :):rockon:
 
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