Hi All New Ducati owner so steep learning curve. I recently inherited my late father’s mid life crisis 996. I have fallen in love. Before I rode it, I sent it in to Rich and Lee at Luigi Moto where it had a full re commission service. I’m now very poor, but it’s given me piece of mind. It came out with one persistent issue…the tacho didn’t work. They spent some trying to find the problem, but to no avail, and suggested it was probably a broken wire somewhere. I have since checked each section of the grey/green wire, from ECU to Tacho, at it has continuity. I can’t find a break. I’ve given the brass screws a twist, fiddled with connectors, and just generally tried to get some life out of it. Nothing. I understand that potentially it needs to be cut open. Before I do this, I was wondering if someone could give me some guidance as to how to do it and what needs doing when it’s split open. Or alternatively…fire away at any suggestions you many have for fixing it. To confirm…it’s dead…there is nothing happening! Cheers in advance
Welcome. You could try a second hand Tacho to see if it’s that? If it is an SPS model however you will need one suitable for a P8 ecu - these are very hard to find. I would have thought though that Louigi Moto would have tried that already so if they couldn’t fix it then it may be a more difficult job.
I am on the hunt for one to help with my diagnostic work, but Rich did tell me he had tried another one and it didn't work either. I believe the ECU was giving out the appropriate signal......but somewhere between there and the needle something isn't working. Like I said, I've got continuity from the ECU connector to the white connector that goes into he back of the tacho.....so I'm baffled! Italian electrics! I'm half expecting to go out one day and find it's just working and something else has stopped. Does anyone know how the tacho is earthed? I've not got my head around that yet and is probably worth a look (although the tacho is powered up and all the lights are on)
The tacho wiring is pretty simple. Two wires providing +12v and -12v plus a signal wire from pin 24 on the ECU. Voltage is easily checked with a multimeter but the signal wire would need an oscilloscope. As suggested trying a working tacho on your bike or your tacho on another bike would give a quick result. If no joy with that then it could suggest the ECU itself is faulty. The earthing is just linked into the earth for the dash lights. wiring diagram on this post https://www.ducati.ms/threads/need-a-996-wiring-diagram.75357/
Thanks Ok, that's all useful info. It's deffo getting the voltage My assumptions so far are it's either: - the grey and green wire (despite the continuity across the bike) - the tacho is broken (although Rich trying one and it not working either would seem to make this unlikely) - the output from the ECU is off (however I'm sure Rich said he checked this and it was fine - might call him and double check). I suppose in theory the only other issue could be the white connector that goes into the back of the tacho isn't making a proper connection with the pins? Can ready the continuity using a multimeter but when you plug it in it's not playing?!? However I would then have thought the wiggling might have made it work. I think I best ready up on cheap oscilloscopes. Any guidance on how to test the ECU output would be appreciated, as this is a step up in electronics for me!
although fault not rectified (npi) and not a P8 ECU, this thread will add some info, and there are more on here if you search. https://www.ducatiforum.co.uk/threads/rev-counter-not-working.50065/
Hi Chris Again much appreciated. That is the post that I have pretty much followed to date with regards to checking the wires etc. Sounds like I need an oscilloscope to check the ECU output. I've not gone into rectifiers etc yet. Focus to date has been on cables, connectors and the tacho itself I'm tempted to open the clock up, but would rather know what I'm looking for before I get the grinder out! With regards to ECU type, I believe my bike has the 16M not the P8 (big connector is on the side) Cheers Alex
Sorry, i've confused things as thought you had a P8. Ideally you could briefly swap out your ECU to try and solve the problem, as it sounds as though every other avenue has been tried apart from verifying trigger pulse from ECU.
1. Check the Tachometer Signal with a Multimeter: Locate the tachometer wire: This wire connects the IAW16M ECU to the tachometer. (Pin 24, green/white wire) Set the multimeter to AC voltage: A tachometer signal is typically a varying voltage (AC). Start the engine: Allow the engine to idle. Observe the multimeter: The multimeter should display a fluctuating AC voltage.As the engine speed increases, the voltage should also increase. 2. Check the Tachometer Signal with an Oscilloscope: Connect the oscilloscope: An oscilloscope provides a visual representation of the signal's waveform. Observe the waveform: The tachometer signal should be a square wave. Verify the frequency: The frequency of the square wave should correspond to the engine speed, with each pulse representing a firing of the ignition coil (or other relevant signal).
Fantastic post. Thank you I can do the multimeter test so will take the nose off and have a go at the tacho end. At least that will pretty much rule in/out the ECU and wiring.
Or a tacho, I have termis on mine, different chip I think, send me a pic of your ECU and I'll compare to mine
Hi Ivor Well that was a bit tongue in cheek from me.....but thank you for putting your hand up! I'm Carmarthen so I may well give you a nod in due course and see if there is any potential to do something if I can't get to the bottom of it. Mine also has termis and the relevant chip.
Have a good look at your multimeter - it may have a frequency (Hz) measurement setting if it's a good one. If so, pop it on the signal wire and see what you get. I disagree with this from Chrisw: "...Observe the multimeter: The multimeter should display a fluctuating AC voltage.As the engine speed increases, the voltage should also increase..." If you're going to try the AC voltage setting, the voltage should stay the same with increasing revs - it's the frequency that'll increase. This is what you'd see happening if you use an oscilloscope (or if you've got a suitable multimeter)...
Mine doesn't, but I can easily get my hands on one that does. Will do some investigating and report back Thanks again for all input to date. Really appreciate it
