Ford Focus: Check Engine Light & Error Codes

Translated on 20-10-2026, 5:53.

hello

I currently have a Ford Focus, model year 2004, with a 1.8 TDCi engine, and I want to swap it with my VAG car.
Check error codes.
That won't work.

What am I doing wrong, or is there a problem with Vag?

Best regards,
Andy

Translated on 20-10-2026, 5:54.

Hello.
The name VAG-COM comes from Volkswagen and Audi, Ford is a different corporation, and also uses a different protocol with different pins for data transmission (PWM according to ISO 1850). VAG uses ISO 9141. Through the OBD2 interface, data can only be read if this protocol is also supported.
Regards,
alsch

Translated on 20-10-2026, 5:55.

With the current VAG-Com version, it is possible to read data regardless of the manufacturer via OBD2. Which version do you have?

Translated on 20-10-2026, 5:56.

Quote:

"With the current VAG-Com version, it is possible to read data independently of the manufacturer via OBD2"

.

Not quite. As mentioned, Ford uses a different protocol via different pins (I believe pins 2 and 10), so it only works with OBD2 interfaces if they support ISO1850 in addition to ISO9141, which VAG-COM cannot do.
Ford vehicles from 2004 often also use a CAN-bus system for diagnostics. I'm unfortunately not sure how VAG-COM OBD2 works with that. It might be possible to use a Hex-Can interface – maybe. I'll try it out next time I get my hands on a Ford with CAN, but I haven't had many of those yet.
Best regards,