I have been trying to get an OBD II diagnostic lead to connect and work with a 2015 CFMoto CF650NK with Marelli ECU without success and wonder if anyone can help.
I've been told by CFMoto in the UK that you can use Ducati diagnostics directly so have obtained a copy of JPDiag software for use with Ducatis etc plus a Fiat diagnostic lead compatible with the diagnostic port on the bike which outputs to an OBD II connector and an OBD II to USB lead to connect to a computer.
After a first attempt where I couldn't make the connection an assumed a faulty lead, I obtained a replacement and carried out all the cable tests without connecting to the machine which verified that the leads were doing what they should so went ahead and connected to the bike.
At this point I couldn't get any communication so disconnected from the machine and repeated the cable tests where I found that the OBD lead had failed again. I also have a cheap universal OBD scanner which I had used successfully on my other vehicles so I tried this, only to be served up with a "Communication Error" once it had completed its initialisation sequence. When I reconnected it to my other vehicles where it had previously worked perfectly, now I got the same communication error so it would appear that connecting to the CFMoto is sufficient to destroy OBD leads and devices,
I then checked the outputs at the bike's diagnostic port against the wiring diagram and the corresponding pins in the OBD connector and found that of the three pins in the diagnostic port, the ground and K-line ones were as expected for OBD standards but the L-line, which is connected to pin 15 of the OBD connector, was connected to pin 1 of the ECU's permanent connection to the 12V positive terminal of the battery.
OBD standards tell me that the output on pin 15, if used, should be the same as pin 1 of the OBD connector. Additionally, I believe the diagnostic port on a Ducati only uses the ground and K-line, the adapter lead to the OBD lead taking power from a crocodile lead from the battery to pin 16 of the OBD connector. I now believe that the 12V supply on the L-line is what is killing the OBD devices so I would like to know whether pulling the L-line pin from the diagnostic port would get the diagnostics to work and save my OBD devices.
This machine is displaying a self-diagnosis code which says that both exhaust oxygen sensors are open circuit, yet all electrical checks tell me the signals are being supplied correctly to the ECU. I don't want to spend £500 on a new ECU, which may or may not be the problem, until I can perform a proper diagnostic check, so any help in sorting this out would be appreciated.