Could someone enlighten me on the OBD interface.

wassap · 2 Aug 2007 at 22:17

Hi guys, im looking to incorporate some form of diagnostics intot he CARPC im gonna build, but im not so sure on how the diagnostic side of it will work, i think a lot of modern cars use the OBD2 interface, which is something i know nothing about.Does anyone know how it all works, im guessing its some sort of RS232 interface, or is it a CAN bus interface?

Basically its going to be something that can read from a MK2 focus (ST)

Cheers for any info.

Dogbreath · 2 Aug 2007 at 22:45

You know they say 'the great thing about standards is that there are so many of them'? That is very applicable to ODBII, as there are several different methods of communicating with the ECU and most cars only support the one type. The Focus I am almost sure uses a CAN BUS (ISO 15765-4) based system

Something like this interface is probably what you want, since interfacing with a serial port is far simpler than handling the CAN bus directly.

fish · 3 Aug 2007 at 04:19

after 96 cars used the OBD 2 system however in europe after about 99 ish all cars use the EOBD system. Same basic principles but more advanced than OBD 2 also each manufacturer has their own slight variation on the system with the same core components.

Ring Peace · 3 Aug 2007 at 08:36

I have no idea personally but wikipedia is my first stop for anything like this so try this

On Board Diagnosis

siztenboots · 3 Aug 2007 at 09:00

There are quite a few open source projects that you could adapt , rather than having to understand the software protocol and adaptor interface details.

I use an elm327 interface with usb and that supports every interface I could find

KWP2000 is the software, you want for advanced datalogging.

wassap · 3 Aug 2007 at 09:40

siztenboots said:
There are quite a few open source projects that you could adapt , rather than having to understand the software protocol and adaptor interface details.

I use an elm327 interface with usb and that supports every interface I could find

KWP2000 is the software, you want for advanced datalogging.

Thats the one i was looking at last night.

Cheers for the advice so far guys