I’m chasing a cooling fan problem on a 998, tried most obvious things, I’ve got 5v at the coolant temperature sensor, I’ve changed the sensor, the fans run briefly when key is turned but sometimes stay on…..all a bit weird. Bike runs perfectly other than this but the fans don’t come on when it gets hot. Things are maybe pointing towards an ECU fault. Standard ECUs are rare but I’m sure I’ve read that it’s possible to use another ECU from several other bikes and have it flashed with a standard 998 map, but I can’t remember which bikes they may be, 1098 etc. Can anyone shed any light on this as it’s a lot cheaper than ECU repair. Numbers on mine are: 998DUCATI1014 S16DH023
You need to source an IAW59M HW010 ECU. This opens up one’s from the likes of the ST4S and early 749/999’s (with the immo disabled in the reflash) This should fit the bill. https://www.ebay.co.uk/itm/29579319...gyq9EtCRF2&var=&widget_ver=artemis&media=COPY If you Google ‘JPDiag Database’ and search IAW59M it will list the later bikes that used that ECU together with their map refs and software versions. If you put in the map ref for the eBay listing (28640701A) you will see it is an IAW59M.
Have you tried earthing the middle wire of the diagnostic plug. It is a 3 way Superseal connector and should have a cap. The earth wire is the middle connector.
Hi Chris, no I've not tried that, what would that do/prove/eliminate? Would I need to earth to the frame?
The fans being on all the time with the IAW5* family are usually associated with a polarity inversion at the battery. This causes damage to the internal earth of the ECU. This can be corrected by earthing the ECU via the diagnostic connector. If you have the Fiat adaptor for connecting JPDiag/Guzzidiag ETC then you can test if it will work by just connecting the adaptor to the diagnostic port and putting the black fly lead to earth. If it works you can just leave the adaptor connected or tap into the earth cable on the diagnostic port and run a wire to earth.
Thanks chris, fans aren’t on all the time, first time I rolled the bike out this year I turned the key on and they did run constantly. I fired the bike up and the problem went away. Now they sometimes come on for around 20 seconds then switch off but they aren’t coming on when hot in traffic. All over the place really.
Well bugger me, she's all running perfectly again. Fans are kicking-in at somewhere near 100C on the gauge, running until the temp drops a little, switching off as expected and then coming on again when the temperature creeps back up. Maybe that temp sensor that I changed was indeed a bit hissy. I'm going to invest in the cables for JPDiag so I can see faults from now on, but for now fingers crossed all is well.
I helped Ducati John with a 999 that had fans on all the time. Connected the cables for JPDiag and the fans stopped. Removed the cables for JPDiag and everything was fine. To this day we do not know why the fault cleared.
