Breakdown, ignition failur Rt cylinder

Hi and help
We are on holiday in N Spain & yesterday the bike started popping when engine braking with small throttle openings.  Then in the middle of a real cloud-burst it cut out on the right cylinder, at first intermittent then completely. Got back (slowly) to the place we are staying: 35 miles. catalytic convertor red hot visible from behind! Probably burning fuel!  

Looked at it today.

Rt pipe cold when running. Seems to start on two and immediately drops to one cylinder ticking over at about 1,050 rpm. SERVICE warning showing plus red triangle. But only diagnostic error shown is an historical Dashboard code DSB07, nothing in current or in ECU error codes.

Checked and, cleaned all fuses, coil wring and HT. All looks good except rt plug wet. Swapped plugs, caps, leads and coils left to right: problem stays on right cylinder.

Checked ECU plugs both intact, clean, no corrosion.
Tank off, checked all wiring, no damage no visible problems.

Re-assembled, started on 2 dropped immediately to left cylinder only and same error code showing.

Help please any ideas??

Spark plug.

Still on the original plug caps? That's the most likely cause. Source SB05E or F caps and it will probably cure it.

Thanks but
Ngk 05 angled caps fitted, tight and no sign of damage. Swapped and the problem stayed on the right side

maybe try a compression test

Valve gear on the right looks good... but will check compression on return home

I would like to disconnect the right side injector to reduce the fuel wash in the "resting" cylinder when i ride the 210mile home. With the injector disconnected it shows errors ecu25 and ecu31. Any advice?

No, it's not happy with a disconnected injector.

Apologies for the spark plug comment. I didn't read your first post properly.


If swapping everything left to right didn't change anything, it can only be the lead from the ECU*. Check the ground (Red/Brown wire) and pop the ECU and check the pins.






*I mean electrically.

ECU popped all pins bright and clean all sockets clean.
WD40 applied {no vaseline here} reassembled, no change in performance or error codes.

So cant disconnect injector to ride back?...meh!

Fear it is dead ECU

Got access to a multimeter? Check it's got 12V on the lead from the ECU.

Use a 14 -15 ohm resistor to short out the injector lead. Not a 1/4 watt. 10 watt +

Everyone fears it's a dead ECU. It very rarely is.

hey, which part of northern spain? I could potentially lend you a hand or tools

Hi i am in Poo de Llanes but have friends helping.

The only tools i need are crimpers and crimp connectors, going to try Posada de Llanes for those tomorrow unless you know better.

Hi Lazlo
Please what are the Spanish/Basque words for
(1) crimp connectors and crimping pliers?
(2);the sort of shop where i could buy them?

Thanks

@beetle have isolated signal and switched earth wires to & from right coil. I cannot see a connector block in that circuit, am i missing one?

Huh? I thought you'd determined the coil was OK?

Yes coils swap shows both coil-wire-cap-plug sets are fine. Brown-stripe-on-red switched earth works for both injectors and left coil.  

So am looking at continuity between ecu brown connector pins 10 & 38 and coil connectors. Just bought a multimetro then back to the bike

My apologies. The red/brown wire is +12V from secondary injection relay. The ECU grounds the coil via the blue/green wire to fire it. Amongst other things, the fuel pump is also powered via the secondary injection relay. You should have +12V on the red/brown wire with the key on.

Thanks, misread the switching lol

Multimetro results continuity test
between (1)Left coil connector orange/green to orange/green at 38 on brown ecu socket = 100% connectivity no breaks, damage or resistance
Between (2)  Right coil connector blue/green and blue/green at 10 on brown ecu socket. 100% connectivity no breaks, damage or resistance
(3) 100% continuity between left and right red/brown coil wires

Coil feed and earth measurements (With battery in 12.6v, ecu replugged)
(1) left (working) side
_a) ignition off:
__(i) brown/red 0.01v falling to 0v
__(ii) orange/green on 0.01v falling to 0v

_b) Ignition switched on:
__(i) brown/red 0.01v falling to 0v
__(ii) orange/green fluctuates then settles at0.04v

(2) right (no spark) side
_a) ignition off:
__(i) brown/red 0.01v falling to 0v
__(ii) blue/green 10.47v  rising to 11.05v

_b) ignition switched on:
__(i) brown/red 0v
__(ii) blue/green 9.4v fluctuating 0.2v

Don't like asymmetric outputs from the ecu

Gack!


It certainly does seem like a an ECU issue. SSR or gate stuck in the wrong state, maybe.

There's no circuit diagram for the ECU, so just guessing. Might be worth disconnecting the battery +ve and switching the key on to let any caps discharge in the ECU. Might unstick it. Long shot. Alternatively, find the nearest Ducati and knock of its ECU.

After you figure out the ECU if you bike doesn't want to rev you might've melted part of the catalytic converter causing a restriction in the exhaust. That's what happened to me back when I had plug boot issues on my 2009 and had to ride it a ways on one cylinder to get back to civilization.

Beetle said
"Might be worth disconnecting the battery +ve and switching the key on to let any caps discharge in the ECU." Thanks i will try that

The MuffinMan said
" might've melted part of the catalytic converter causing a restriction in the exhaust"
That is there other reason i want to ride with that injector disabled. I will get a lift in a van to Bilbao so only the last 95 miles to ride.

Replacing ecu, 2nd hand ones rare at £250 and up new at £1000. Can i use any w5am and just plug and play with existing dash, keys and lock? Or is it more detailed than that?

lcjohnny wrote:

Beetle said
"Might be worth disconnecting the battery +ve and switching the key on to let any caps discharge in the ECU." Thanks i will try that

The MuffinMan said
" might've melted part of the catalytic converter causing a restriction in the exhaust"
That is there other reason i want to ride with that injector disabled. I will get a lift in a van to Bilbao so only the last 95 miles to ride.

Replacing ecu, 2nd hand ones rare at £250 and up new at £1000. Can i use any w5am and just plug and play with existing dash, keys and lock? Or is it more detailed than that?

If you can afford to wait I can slip one in a baggy and send it over? You’ll need to stick a suitable map in it but if it cures the problem then at least you’ll know it is the ecu. If it is? Just find a Ducati W5AM with the same HW number and you’ll be good to go.

I’m still a bit skeptical as the only one I’ve ever replaced was actually *Physically* damaged!

This is why I like this forum so much. Thanks to all for sharing knowledge and ideas.