ECU unplugged

Hi,
This my first post and my first moto Guzzi motor Bike, I bought my bike from another forum member and have had it since the 9th of December and rode it back from Sydney without any issues, I have rectified some of the butchery on the bike and bought it back to standard, The situation so far, After a ride of about 130 KLM I parked the bike at a friend's place and when attempting to start the bike, the fairy of the UCU disconnect paid me a visit with the same symptoms as stated in the other posts I have read on the forum, speedo does the sweep and check, all lights go out the fairy arrives and the red triangular light appears, I was close to home so I coasted the bike home and had a look, at this time I was not thinking straight about the faulting finding process, after pulling the main fuses to check, none blown, I reinstalled them and the fairy left and the bike started, I rang Peter the GRiSO whisperer and he advised me it might be the earths, I cleaned all of the offending terminals and the bike started a lot better.

Part two.
After my last ride on Sunday in the Mary Valley, the bike was running fantastic, once I arrived home, I turned off the bike and cycled the ignition switch, on the third time the fairy of the UCU disconnect appeared, this time I was ready to fault find.
1 - No blown fuses.
2 - No damage to the speedo sensor cable as I had removed the tail piece to rectify the wire done by chicken electrical.
3 - Went into menu and looked for any codes, no codes present on either the ECU or speedo.
4 - Pulled the 40 amp fuses and a noise came from the front of the bike and then stopped, like a vibration.
5 - When I plugged the fuse back in, the same noise came from the front and stopped.
6- Speedo returned to normal operation after the two 40 amp fuses were reinstalled.

One thing Peter advised me to do was install an extra earth to the ECU, I had not done that at this time, so I removed the ECU from the most stupid location on the bike, I inspect the plugs and socket for water egress, but they were both dry and clean, what genius thought it was a good idea to mount the ECU with the plugs in that location, I check the blue earth lead with the multimeter and it has no resistance, I then ran a heavy earth wire with soldered lugs from the frame horn mount, to the ECU earthing point. Also, the battery fitted to the bike was smaller and had been packed up with spacers at the bottom, I have replaced the battery even though it tested Ok with the correct size battery that fits the bike, the bike has no power drain and the only accessory hooked to the battery is a USB charger that is switched. I cannot see anything on the bike that I have done that would cause this issue.

In my handbook it shows the ECU disconnect symbol but fails to explain what it is, my questions to the GRiSO brain trust are as follows.

1/ - Can anyone tell me what the ECU symbol actually means.
2 - Has any member had the same issue as I have described without the blown fuses.
3/ - Can anyone tell me the steps taken to eliminate the problem after the fairy visited them.

Any input would be greatly appreciated as my past career involved a lot of problem solving on high speed rotation equipement in offshore oil and gas but on the electrical side my experience is lacking.

Regards,
Shayne.

The ECU disconnected symbol simply means the Dash has lost communication with the ECU. They communicate over CAN bus.

There are a few reasons for it. Either the ECU has gone to sleep or lost power (either by loss of ground or poor +ve), or the Dash has some sort of fault or connection issue.

It also appears when writing a map.

I’ve never had a visit from the fairy for the first two scenarios.

Peter has offered me a loan of his spare dash if required and should the dash throw a code if this happens while this has never happened while riding the bike..

This is an odd one. In my experience if the ECU is bricked it stays bricked. It's not something that comes and goes or can be rectified by pulling and replacing the power fuse.

Now a dash problem is a possibility, unlikely, but a possibility. I can send you my *Spare* dash as a loaner but I really don't want it used, as in ridden anywhere, as it's brand new and since I will eventually be selling it if I don't use it before I give up riding I'd like it to stay *New* as a used dash with miles/Km on it obviously isn't worth as much as a brand new one. Perhaps disconnect the speedo sensor when doing the tests? Yes it would throw up a 'Service' warning but I'd expect the ECU disconnected fault would override the service fault.

I'd still suspect some sort of Canbus interruption, possibly in the loom, but really at the moment it's pretty much impossible to say.

Thanks peter, I check the plug on the speedo yesterday and there was no corrosion or any sign of an issue, I have not ridden the bike since I pulled the ECU and added another earth to the unit, if you ever want to sell the speedo, please let me know.

At the moment they are still available to the best of my knowledge. I'll check the price today. Surely though it would make sense just to borrow mine first as if yours is fine there's no point in spending a grand on a spare one?

Quote :

was close to home so I coasted the bike home and had a look

When you were at your friends place, were you eventually able to get it started? Or does “coast” mean you pushed it home? Details are important.


Is the ECU disconnect now hard on? Or intermittent? The reason I ask, is because the engine will start without the dash connected. If it starts without the dash connected, the fault lies in the dash (or wiring). If not, then it’s the ECU (or wiring).

I just coasted down the hill to home, I made an attempt at his house to start the bike but did not pay attention to the actions I took as it was the first time this had happened. It has happened only twice, once after a ride at my friend's house and in my workshop after a long ride, it appeared after I cycled the key about three time. I had turned the engine of and was trying to see if the cleaning of the earths had fixed the problem.

Pete Roper wrote:

At the moment they are still available to the best of my knowledge. I'll check the price today. Surely though it would make sense just to borrow mine first as if yours is fine there's no point in spending a grand on a spare one?

I very much appreciate the offer Peter, but you mentioned you did not want it ridden, unfortunately, the fault only appears after a long ride. I might invest in a new dash as a spare while I am hoping for a ride today.

You might want to try the “discharge” trick. Disconnect the battery and bolt the +ve & -ve cables together Switch the key switch on, and let the capacitors in the dash discharge overnight.

If that doesn’t work, try disconnecting the dash for 3-4 days. I once had problem with mine where all the blinkers were constantly on. Not blinking, just lit up. I had the dash off for a week while I contemplated my options. I reinstalled it just for grins, and the problem was gone. Fuctifino.

Thanks beetle, I have bought a new dash as I want to keep the bike and have some spares.

Mine does it occasionally in my case its the big relay it sometimes wiggles loose I now routinly make sure all the relay are seated properly. These are all located along the frame under the side panel I remove some screws to flex it away but dont apply too much or it may crack like mine did

Thanks Tim, I spoke to Peter, and he said no relay in the circuit for the this, but I will check them out.

Its a pain but I traced ot to loose relay . I slapped the side and it correvted tjen i seated all of them after some contact cleaner but Pete knows these bikes better

Thanks again Tim.

Bugger, I forgot to post the dash today! Sorry, I'll do it tomorrow before I take my old boiler off for her 70'th birthday break in Huskison!

Old boiler, eh? I'm dobbing you in!

You don't know what she calls me!

Hi Pete, I unplugged the dash and the ECU and it appears to have fixed it, it might have been a pin with intermittent contact, touch wood.