Hi, I have an issue with a 04 Ducati 749. when I turn the ignition on the both radiator fans come on and they turn off after about 30 seconds it turns over but won't start,if I turn it off and unplug the fans it fires up but doesn't seem to be running right, it also doesn't read the temperature with fans plugged in or not. it's got the engine management light on and is giving me error codes 1.1 and 3.1, I changed the temperature sensor still the same. its also running a ecu that goes with the exhaust and has been stood for few years with a flat battery. I also refitted the original ecu it primed the fuel pump but nothing,wouldn't turn over but reads the temperature,put other ecu back on same as before, hoping someone can help, thanks for your time.
1.1 - TPS disconnected 3.1 - Temp sensor shorted to power supply Coil/injector/pump relay should be changed as they cause all sorts of problems if corroded. The fans being on at ignition is usually a sign of polarity inversion to the ECU. Jump starting, battery connected wrong way or diagnostic lead connected wrong way can cause this. An internal earth in the ECU has fried. There is a work around where a wire is run from the negative wire of the diagnostic port to the battery negative.
Does the wire need to remain permanently in place or does it somehow reset the polarity and can then be removed? Have never been entirely clear on that, Chris.
Hi and thanks for all the advice and yes it was the internal earth on the ecu and the wiring loom was no good, all up and running now only other problem I had was with the rear brake master cylinder packing in and finding a rebuild kit, which Ducati don't sell.but after a bit of head scratching and searching BMW will they use the same master cylinder on their f650gs, so happy riding and thanks again
I have the same problem with my Monster S4 (2001). When the ignition is switched on, the fans kick in and stay on. The bike was stored for a couple of years in a domestic garage before i bought it - is this likely the same problem? Battery is also pretty dead so the bike may have been jump started by previous owner. Any advice welcome.
See if a new battery sorts things out. Do you have the JPDiag/Guzzidiag cables? If you do and the problems persist then fit the Fiat adaptor to the diagnostic connector and attach the black fly lead to a good earth. If that sorts issue then splice a wire into what is the middle wire on the 3 way diagnostic connector and then run that wire to battery negative or a good earth. Fiatadaptor can be removed. That should sort things.
Thanks for the advice Chris, I don't have the diagnostic cables yet - I'm a new owner! I'll try the battery route first
