Question about ELM327 and CAN-Bus

[Antoniokodo]

Hello everybody

Seems like there isn't any New user's Thread, so I start posting my first question

I own a Lancia Thesis 3.0 V6 A/T wich has issues with Can Network, but first problem I have is that when the ELM 327 (buyed from electronic-fuchs.de, as recommended on here) is plugged on the Obd, the whole Can Network falls down, no gear, revs, engine temp displayed on dashboard and lots of warning error from another modules..

The thing is, from the diagrams, looks like the Can Network pins on the Obd goes to Diagnostic interface inside the Body Computer, not the pins directly to Can Network wiring harness, right? To be right, CAN goes down when the ELM is connected to USB on the laptop, if I only connect it on the OBD, all seems fine. The interface was tested on an Alfa Romeo 159 Jtdm 16v and worked fine.

Thanks!

[s130]

Are you running the laptop from a power source other than it's internal battery?

I understand that some vehicles are more sensitive to "ground loop" currents/interference than others.

Try again ensuring the ONLY external connection to the laptop/pc is the ELM cable only.

[Antoniokodo]

Yes, I've tried as you said many times but with I ended with same problem. Now I understand the CAN-bus arrangement on this car a bit better, seems like there isn't any diagnostic interface, only B-CAN (Body) is wired to OBD pins 6&14, while ECUs present on Drivetrain CAN (C-CAN) are diagnosed through K-Line.

Well, I've managed to at least fix annoying CAN-B related DTCs changing NIT module and doing proper alignment. Now I'm left with Electronic Parking Brake error warning on the instrument cluster, but MES doesn't have the ability to talk with it, so bad..

See you, thanks