No headlights... not the sub harness... ECU?!?!

avc8130

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Let us know how this turns out.

Does the ECU ground perform any other function than just the headlight?

ac
 

Brick

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That pin/wire out of the ECU only goes to turn on the relay which turns on the headlights. I don't see it going any other place.


Brick
 

Kevhunts

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My guess is Yamaha will cover this as it is some what of a obvious safety issue. ::008::
 

SuperJimbo

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The more they overtake the plumbing, the easier it is to stop up the drain. Bloody damned computers, up their shaft....
 

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Yamaguy55

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Stoopid question:what happens when you apply the ground at the ECU that the ECU should apply to make the lights come on? I ask this as my WR250R had an over temp issue a few years back because it was idling and the fan never came on. I artificially applied a ground at the ECU where it should have provided one to activate the fan on it's own. There was a logic hangup that then cleared and it has worked ever since. Those IC level "relays" internal to the ECU can partially stop working. It is a problem of any SS contractor, and may or may not clear.
I have to admit the older relay method was better. But we have ECUs, so we have to live with them.
 

Brick

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Yamaguy55,
Great question as I've not done this yet... And want to. And will do this as I too have been thinking I need to see how the headlights will function IF I install a lighted switch between the relay to ground as my on/off switch for my headlights.
However, the relay that is not getting the ground is not an IC relay it's a full size relay that is on the side panel. It's the top left one when you take both right side covers off. Any way one of the out pins from the ECU goes to this relay providing the connection that closes the relay allowing 12 volts to the H7 bulbs that are the headlights.
So I don't believe anything is going to be reset but I'm gonna make the test anyway.


Brick
 

Yamaguy55

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Brick said:
Yamaguy55,
Great question as I've not done this yet... And want to. And will do this as I too have been thinking I need to see how the headlights will function IF I install a lighted switch between the relay to ground as my on/off switch for my headlights.
However, the relay that is not getting the ground is not an IC relay it's a full size relay that is on the side panel. It's the top left one when you take both right side covers off. Any way one of the out pins from the ECU goes to this relay providing the connection that closes the relay allowing 12 volts to the H7 bulbs that are the headlights.
So I don't believe anything is going to be reset but I'm gonna make the test anyway.


Brick
When I say IC relay, I mean within the ECU. Not the mechanical external one.

I (sadly) do this for a living, and the solid state things that act as switches and relays often hang up. I find them at work all of the time. Sometimes they recover, sometimes they are done.
 

Brick

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Yamaguy55,
Yes I knew what you mean and the relay that is not getting the ground is NOT in the ECU. I suppose there could be one IN the ECU that's not outputting the much needed ground.
Thanks I will post my findings when I run this test.


Brick
 

Yamaguy55

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Brick said:
Yamaguy55,
Yes I knew what you mean and the relay that is not getting the ground is NOT in the ECU. I suppose there could be one IN the ECU that's not outputting the much needed ground.
Thanks I will post my findings when I run this test.


Brick
That's what I meant: there is some sort of solid state device within the ECU that changes state, and applies the ground. Essentially, it is a solid state switch, relay, whatever you want to call it. They can get stupid and hung up in one position, for lack of a better term. We use these things throughout the equipment I work on. Sometimes by artificially applying the ground with the device in circuit makes them wake up, sometimes not. Many times it is current flow. Unlike traditional mechanical contact relays, they require a certain current flow to switch states. You can have the voltage, but not the current, and they won't work correctly, or at all. One way to prove this is an external wire from the actual physical headlight relay to the connection at the ECU, with everything hooked up normally, just the additional conductor. Use something larger than standard wiring to be sure you get good amp handling ability..If it suddenly starts working, there's a bad connection or too much resistance in there somewhere. It wouldn't hurt to start pulling connectors and perhaps spray with WD40 and refit. Silicone grease would help as well. I suggest Dow Corning DC4. One tube would last you a lifetime. I use it at work and it delivers. It will prevent moisture from creating bad connections due to corrosion/contamination. Use sparingly. Works great on spark plug caps/coils: you can get them back out! (use anti-sieze on spark plug threads, not this stuff)

Question: I didn't see if you said it: did you ride in the rain/wash the bike/etc just before this started? if so, I would think there's a possibility of the bad connection I'm talking about. The connectors we have are good, but the submicroscopic wiring will give problems if everything isn't making good contact/connections. I' found the fan thing on my WRR by going from connection to connection and finally grounding the connector pin at the ECU that activated the fan relay. I've since gone through the bike several times (The WR) and have checked and reseated connections everywhere I could get at them. I've had no problems since.

The ECU could be bad, but I'd check everything else first.
 

Brick

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Ok I made the check... I added a ground to the relay. Note I didn't go to the ECU because 1) it's a real pain to get to and not even sure I can open up the back of the connector to access the pin while its still connected to the ECU. And 2) when we had the ECU out we checked the wire between the ECU and the relay. It had 0 ohms resistance. We had also wanted to be sure that the wire from the ECU went directly to the relay and not somewhere else first.
The result = No headlight! So it didn't reset and so it's more of an indication that I need an ECU.
Come on Yamaha... come through for me!



Brick
 

Yamaguy55

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Brick said:
Ok I made the check... I added a ground to the relay. Note I didn't go to the ECU because 1) it's a real pain to get to and not even sure I can open up the back of the connector to access the pin while its still connected to the ECU. And 2) when we had the ECU out we checked the wire between the ECU and the relay. It had 0 ohms resistance. We had also wanted to be sure that the wire from the ECU went directly to the relay and not somewhere else first.
The result = No headlight! So it didn't reset and so it's more of an indication that I need an ECU.
Come on Yamaha... come through for me!



Brick
I'm lost. Start over.
- You grounded the wire to the ECU/headlight relay and the light didn't come on?
- if that is the case, it is back towards the headlight.
- Maybe I read it wrong, but if you did what I understood you did, the ground should complete the circuit and energize the headlight relay, and away you go.
- If not, then it is time to check the relay again.
- If you have power to the relay coil, add a ground, the relay should cycle on and off. If you supply that ground between the relay and the ECU, and it doesn't work, it isn't the ECU. It is either insufficient current to operate the relay, sick/bad relay, wiring to relay, or wiring to headlights.
 

Brick

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Hmmm now I wonder if I had the wrong pin... I need to get my MC mechanic friend back over here.
You are right I got confused. Thanks.


Brick
 

greg the pole

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sorry to make things even more complicated for you brick.
Did you try things the other way round with your friends bike?
Your relay in his harness etc...

Also, if you look at the wiring diagram, the relay coil has a diode between the negative (from ecu) and the positive (from accessory when bike is turned, on and running), for what purpose I do not know. It's been a while since electronics class, but if I'm not mistaken, I diode is a one way street. Allowing flow of current one way, and blocking it the other. In this case, I think it goes from negative to positive. Again, it's part of the relay, so if the relay/diode is bad, then your replacement should work...if the above conditions are right.

The way I looked at the diagram, is that if, the bike is running, you should have 12 VDC on the one side of the coil, and a ground from the ecu. You should be able to ground from the battery to the negative terminal, when the bike is on, and things should go on for you.
Failing that you can also temporarily bypass the relay, and jumper the two open contacts to see if the power goes through cleanly.

I still think this has something to do with the original wiring harness. In some instances, the damage was done beyond the headlight harness, and into the main harness.
 

Yamaguy55

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greg the pole said:
sorry to make things even more complicated for you brick.
Did you try things the other way round with your friends bike?
Your relay in his harness etc...

Also, if you look at the wiring diagram, the relay coil has a diode between the negative (from ecu) and the positive (from accessory when bike is turned, on and running), for what purpose I do not know. It's been a while since electronics class, but if I'm not mistaken, I diode is a one way street. Allowing flow of current one way, and blocking it the other. In this case, I think it goes from negative to positive. Again, it's part of the relay, so if the relay/diode is bad, then your replacement should work...if the above conditions are right.

The way I looked at the diagram, is that if, the bike is running, you should have 12 VDC on the one side of the coil, and a ground from the ecu. You should be able to ground from the battery to the negative terminal, when the bike is on, and things should go on for you.
Failing that you can also temporarily bypass the relay, and jumper the two open contacts to see if the power goes through cleanly.

I still think this has something to do with the original wiring harness. In some instances, the damage was done beyond the headlight harness, and into the main harness.
I agree. I think the ECU is the symptom. It may also be a problem, but I don't think it started there.

The diode is indeed a one-way current flow device. They are on relays for a number of reasons, often to prevent inductive kick, a fancy pants term for a voltage spike being induced back into a circuit by a coil. In this case, the coil that makes the relay function. Sort of the same principle that ignition coils use to create the spark. That spike can do in the small circuits common in things like the ECU, so that is the purpose of the diode.

I did some other work on my WRR yesterday, and ran it long enough intentionally to see if the fan would come on. It did. The ECU logic hang up I had in 2009 is seemingly a thing of the past. So if the cause of this is found and resolved, your ECU may repair itself. They have been known to do that in automotive applications, I'm sure these are at least similar.
 

Brick

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Ok... guys I did replace my relay because when we checked it didn't work. AND yes I did put my ECU in my buddies bike AND the problem did move to his bike = no headlights.

Re:the relay that is external to the ECU... the one that actually turns on the headlights, well I hesitate to do any more testing on it as well... is it possible that it is a 5volt relay. I mean just the coil part that utilizes the ground output from the ECU? I don't remember why or what but at some point in this "trip" I thought it might be a 5volt relay.

I did NOT hear from any of the Yamaha people today... damn, I would love to hear from them telling me that a new ECU is on the way!
 

greg the pole

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Brick said:
Ok... guys I did replace my relay because when we checked it didn't work. AND yes I did put my ECU in my buddies bike AND the problem did move to his bike = no headlights.

Re:the relay that is external to the ECU... the one that actually turns on the headlights, well I hesitate to do any more testing on it as well... is it possible that it is a 5volt relay. I mean just the coil part that utilizes the ground output from the ECU? I don't remember why or what but at some point in this "trip" I thought it might be a 5volt relay.

I did NOT hear from any of the Yamaha people today... damn, I would love to hear from them telling me that a new ECU is on the way!
as I said before. I highly doubt it. It's a 12V system, all components will run on said voltage, unless they have a resistor in line to drop the voltage.
Besides, your ECU did the same thing on your buddy's bike, then it's the ECU.
 

Yamaguy55

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Partzilla shows they have both of them available. The 2012 model uses a 23P-8591A-30-00, the 2013 uses a dash 70 vs the -30 of the 2012. That must explain the small differences.

$891.00 each. Ouch. Must be made of unobtanium. Or Ukrainium.

Possible suggestion: contact the ECU flash guys. Maybe when they get inside, they can toggle the headlight on circuit. And give you a gen2 at the same time if you don't already have it. If it doesn't work, give you credit towards a flash on a functional ECU.
Worse comes to worse, it doesn't work and you need a new ECU.
 

Don in Lodi

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Don't see why a bike would be different than an auto...
5 volts comes into the picture as a reference signal to the sensors, TPS, CTS, IAT, MAP... it is then a percentage of that voltage getting back to the ecu that tells it what is happening at the other end.
I'd say if the problem followed the ecu to the other bike, the ecu lost a driver is all, it happens, the same kind of driver that fires the injectors, and the coils. You guys that have had one out, are these things filled with epoxy, or are they open air? (should be epoxy...) Don't think you can have the epoxy filled ones repaired.
Another relay triggered by something else, applying/switching the needed ground sig to the light relay is easy/cheap.

 
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