Battery draining through ECU

[dlaing]

David

 

I acually measured the current at a 00' V11 (same black color than mine) across the fuse 1: it was zero!

So it is clear for me that my ECU has a fault. From the fuse 1 one wire leads to the ECU relay and an other one leads directly into the ECU. This is the wire where the current drains through the ECU.

I suppose the ECU needs that positive wire directly from fuse 1 not passing the relay.

Yah, it could be I have two bad ECUs.

 

 

You might save yourself some trouble.

 

I was going to hook up a disconnect switch until I measured the leakage current.

 

I just measured the leakage on mine. It's only 1.12 milliamps! What that means is that the self discharge rate on my battery of just over 22 milliamps is the main factor. That just saved me the trouble of hooking up a disconnect switch, but it means I'll have to check my battery voltage every week or so.

 

Is your electrical circuit different from my '04 Sport so I has more leakage?

I am at 70milliamps across the fuse last time I checked.

The electrical ciruits are a little different between my 2000 and your 2004.

I wonder if I include the disconnect switch into the relay circuitry, would the timing of electric current be an issue? My guess is that it needs the voltage at the ECU before the ECU and FI relays are flipped on, but maybe not.

[Ryland3210]

Yah, it could be I have two bad ECUs.

I am at 70milliamps across the fuse last time I checked.

The electrical ciruits are a little different between my 2000 and your 2004.

I wonder if I include the disconnect switch into the relay circuitry, would the timing of electric current be an issue? My guess is that it needs the voltage at the ECU before the ECU and FI relays are flipped on, but maybe not.

 

That's pretty high leakage. I can see why a disconnect switch would be a real plus on your '00.

 

I could probably answer your question if you could supply the relevant parts of the schematic.

[dlaing]

That's pretty high leakage. I can see why a disconnect switch would be a real plus on your '00.

 

I could probably answer your question if you could supply the relevant parts of the schematic.

http://www.thisoldtractor.com/guzzi007/sch...9_V11_sport.gif

I wish I could find a schematic of the ECU....I have searched the internet for hours looking.

If you read back through this thread, you can see I went through much trying to find the leak.

It really does seem to be inside the ECU.

But I tested two ECUs....actually three, but the third was a Cliff Jeffrie's MY15 and it did not have the problem.

If you feel like reading this entire thread you can feel some of my pain, and maybe have an insight.

Cliff's ECU is certainly a solution, but I have invested TuneBoy into my ECU.

I suspected TuneBoy could have damaged the ECU, but my second ECU has the same problem.

[Ryland3210]

http://www.thisoldtractor.com/guzzi007/sch...9_V11_sport.gif

I wish I could find a schematic of the ECU....I have searched the internet for hours looking.

If you read back through this thread, you can see I went through much trying to find the leak.

It really does seem to be inside the ECU.

But I tested two ECUs....actually three, but the third was a Cliff Jeffrie's MY15 and it did not have the problem.

If you feel like reading this entire thread you can feel some of my pain, and maybe have an insight.

Cliff's ECU is certainly a solution, but I have invested TuneBoy into my ECU.

I suspected TuneBoy could have damaged the ECU, but my second ECU has the same problem.

 

I can offer the following:

 

In the case of some automobiles I own, when the battery is disconnected, the feedback loops which control fuel air ratio go back to the factory default settings. The ECU then has to relearn how to optimize the tuning as the car is driven.

 

I don't know if that is the case with Guzzi's, but my guess is that the models using Lambda sensors also have that issue, while the ones without the sensor are open loop so disconnecting the battery makes no difference.

 

So in the latter case, your leakage could be eliminated by having a relay energized when the ignition is turned on. Its contacts would then simply be wired in series with the supply to the ECU. Many relays come with two sets of contacts, so to get a little extra reliability, you could contect both sets of contacts in parallel.

 

If you want to be kind to your ignition switch, connect a silicon diode, rated at more than the coil current, across the relay coil with the black stripe (cathode) connected to the Ignition (plus) side of the coil and other side to the ground side of the coil.

 

Make sure the pull in and drop out voltages of the relay coil are going to work below 6 volts, and 5 would be better so the ECU doesn't drop out on you when hard starting with a weak battery, but without overheating at 14.4

[dlaing]

That makes sense.

I thought about the possibility of there being some fuzzy logic feedback training, but that would only make sense if there was an O2 sensor. My bike has no O2 sensor, but I think the 15M has the capability built in, and so Guzzi probably just wired it that way.

I suppose I could disconnect the ECU fuse, turn the ignition on, connect the fuse and then try to start the bike.

Worst thing that could happen is a fried ECU but unlikely.

I'll have to think about that diode thing and how to wire it all. It might also be a good time to do the Guzzi Transil Diode modification

http://paaat.guzz.free.fr/diode_transil/english.html

[Cliff]

The ECU has 2 power feeds. One is permanently wired and is causing your drain. The other is keyed and is the one I use on the My15M.

 

Maybe the permanent one can be removed. But it may like to keep itself powerd for updating its own flash at times.

[luhbo]

Cliff,

you overlooked that Your15M shows the same symptomes - in his bike!

 

Some weeks ago Nogbad has posted that his '2000 V11 started right on the first click after some weeks of winter rest, with a 6 year old OEM battery. I can read similar stories in the german forum, so the ECU is probably the wrong trace to be searched.

 

One more thing: I never heard of one defect WM15 (as long as it was left unmodified), David thinks to have even two of them. I do not think so.

 

Hubert

[dlaing]

Cliff,

you overlooked that Your15M shows the same symptomes - in his bike!

 

Some weeks ago Nogbad has posted that his '2000 V11 started right on the first click after some weeks of winter rest, with a 6 year old OEM battery. I can read similar stories in the german forum, so the ECU is probably the wrong trace to be searched.

 

One more thing: I never heard of one defect WM15 (as long as it was left unmodified), David thinks to have even two of them. I do not think so.

 

Hubert

No, you must have mis-read what I wrote. Cliff's ECU was the one ECU that did not exhibit the draining symptoms, simply because he does not even use the wire through which the draining occurred. His ECU only gets power when the key is on.

If you install Cliff's ECU you can throw away the ECU fuse, this is why it would cure my problem.

It could still be I have two bad Marelli ECUs.

The second ECU I got as a backup from someone who went to a Ti ECU.

I have no reason to believe they had modified it. I know I only modified my original ECU.

I wish Wayne would release the TuneBoy diagnostic....I think I'll go pester him.

[luhbo]

Yes, I'm sorry about that. My fault.

 

When I wrote "unmodified" I was talking about hardware mods. Mine went nuts once, but this one was equipped with some aftermarket eeprom. Because the shop that did it was (and still is) a bit nooby they had to remove the original one, replacing it with a soldered socket.

 

I really see no way how a software modification should change the ECU this strange way. If this would lead to any pin left high after shuting down this would mean a remarkable higher drain. That's what I guess.

 

Hubert