Thanks Chris, yes I am am member of Multistrada.net, it's a great group (like this!). I've spent more time on here though cos I also have a 900SS
the things you wake up thinking about. mate, i'll need a wiring diagram but you should be getting battery voltage 12v+ on each coil connection constant when the ignition is on. preferably tested with a test light (not LED) and multimeter. the engine ecu just provides the earth to switch the coil. if you are only getting 2v+ at one coil and 12v+ at the other it suggests a bad connection somewhere between the ignition (fuel pump and ignition) relay to the coil.
Thanks. I’ve just whipped the input wire off the vertical cylinder coil (which runs OK) and only got 2V on that one too. Rechecked horizontal coil input and still 2V there. Battery is showing 12V+ Not sure what to make of that, it suggests that the input to the coil is OK (if it should be 2V, and not 12V), but still no spark. The voltage is on the brown/white wire on both, which looks like a common live, with nothing (or actually 0.2V) on the other wire, which I assume is the one switched by the ECU. Baffled…
2 volts at the good coil doesn't sound right to me - anyone else care to chip in? - am rusty here, but can't see how that can possibly be correct - might go and check one of mine in the week.
Are you certain your battery is good? A decent charged battery at rest can put out 13.5v. The ECU is voltage dependent. The starter motor is voltage hungry. Press the starter and the starter motor takes the lion share of volts. That causes the ECU to shut down due to insufficient volts. You seem to have gone through the wiring for faults. The coil/injector/pump relay is an Achilles heal and should be changed out every 12 months as a service item. I would try a known good battery. After all that has been tried then you may have failed coil drivers. You need to identify which hardware version of ECU you have. HW610 or HW103. That will identify if a replacement is an easy source or a hard source.
Thanks Chris Good question about the battery. First off, it isn't my bike, I'm just helping a mate out (or trying!). He sent two batteries with it, both Motobatt and believed to be good. I have charged them both (but didn't test the voltage with them freshly charged - I'll do this). There's enough in the one I'm using to spin the engine over well. It will catch and run OK on the vertical cylinder, just not the horizontal. I would have thought that if it was an issue with low battery voltage it would run on neither? But good point, I will recharge the battery and check again. Do you have any view on the input voltage to the coils (common brown/white wire). As I said I've tested and showing only 2V on both horizontal (the failed one) and vertical (the one that runs!). I was expecting to see 12 V. Yes, agree about the relay (I had a 1000DS for 6 years and that relay did fail at some point). I have swapped it for the headlight relay as part of the early diagnostics but it made no difference, so I assume it is good (but I'll get a new one anyway). Also - surely if that failed it would take out both cylinders, as the one relay is common to both coils and injectors? Wiring is going to be my next check. As you can see from the two photos at the top of the post, both left and right looms coming out of the ECU have been chopped about a bit - there are 4 wires each side which appear to have been cut and rejoined - presumably an alarm that has been removed. That was to be my job for this afternoon but rain has stopped play. It's a definite possibility that this is the cause of the fault. If the wires are good then the ECU is next on the list. It's a 2003 bike so I'm assuming it will be a HW103. I presume it has to be removed to find the labels, as I can't see anything obvious on it. Many thanks for your help. James
i'm curious as to where you are getting your earth to be reading only 2v+ at the coil connectors. it should deffo be batery voltage at one pin. the other is the earth that is provided by the ecu to trigger the coil. my gut instinct is that your ECU has blown a coil driver.
OK, yes the ECU is an HW103 (removed from mounting and peeled back a label with said "SA07DU32" on it, to find the original Magneti Marelli label underneath). Have now checked/inspected the mysterious chopped wiring. Most have just had a bit of insulation scraped away, presumably a previous investigation looking for voltage. The two that are chopped seem to have continuity, despite not looking great. One of these is the grey/green wire which is a feed to the vertical coil. I could not get continuity on this between where it is chopped between the LHS ECU connection (grey connector) and the vertical coil lead, but on closer inspection, it does go back into the ECU on the RHS (black connector), so maybe interrupted inside the ECU. Have tested both coil input connectors again and same result: Brown/white lead: 2.09V on both Horizonal coil grey/blue: 0.49 V with ignition on Vertical coil grey/green: 0.49 V with ignition on The brown/white wires are actually an earth, as according to the wiring diagram they connect to black which is of course the common earth. So having 2 V on them is not good. That said, I have also found chopped wires to the clutch microswitch by the headstock. These have been cut and reconnected with bullet connectors, which have been wrapped in electrical tape *together* so there is a high probability of a short in there, which could well explain the 2V on the coil earths. What a mess. Anyway, I have sorted that but haven't checked to see if it has removed the 2V on the coil earths. Will go and do that now. But yes, @finm, I am starting to agree that it looks like the ECU is toast...
You can use the JPDiag Database to identify which bikes used the HW103 ECU and the references you are likely to find on the white paper labels on them. Searching ‘HW103’ will give you some results but searching ‘Multistrada’ and ‘Monster’ will give more. The database will help confirm if a second hand ECU is HW103 before resorting to peeling labels. A second hand HW103 will need immo disabling. https://jpdiag.akress.com/modelselect.php
Thanks Chris. There are a couple around at the moment, but no certainty that they aren’t just as knackered as this one. I also see that a HW103 is common to the Fiat Punto! I have an offer of a HW610 with the immobiliser turned off which will apparently run on an 03 bike, so there are options… Cheers James
odd. you wouldn't expect it to run on either cylinder if you are only getting 2v+ from your ignition feed at the coil (via relay) forgive me, you are using the bat negative post for your earth?
Yes. Originally I was using a bolt on top of the vertical cylinder (rocker cover), but now direct to the battery negative. I agree it is odd! There should be nothing on the brown/white and 12V on the others, as far as I understand. I’m going to put the tank back on it tomorrow and see if it will still run on one.
OK, I can tell you're all waiting with baited breath here, so.... solved! It was the ECU wot dun it. On @GTmorgan 's advice I contacted the mysterious "muiriey" through Multistrada.net. I sent him "my" HW103 and he tried it on his bike: result, his only ran on the vertical cylinder, so we can conclude horizontal coil driver failure. He then sent me a later HW610 with the 1000 DS map on it and the immobiliser switched off (so no need to get it coded to the bike keys, etc.). Fitted that and boom, back running on two again. It starts easy but isn't ticking over, so will need a TPS reset (anyone in the Manchester/Derbyshire/Sheffield area help me with that? If not I'll have to get it to Ducati John/Cellier BVT Workshop or Cornerspeed and get it plugged in. Anyway, all sorted. Just going to clean the air filter (posh K&N one), change the fuel filter and give it a clean before I pop the tank back on and I can hand it back to its owner. Thanks all for your help! James
He can setup your TPS, he's got all the kit, offered to do my DS a few years back but it was a 200 mile trip for me.
