I've never needed to connect via an elm327 cable before but after having trouble with the ABS I finally bit the bullet.

It connects to the engine OK but when I try to connect to anything else I just get the ELM327 unable to connect to ECU message.

Can anyone advise what I'm doing wrong please?

It's set up as elm327 v1.3+ on a valid com port, passes the test OK and connects to the engine diagnostics fine but won't connect to anything else.

Is there anything else I need to do? I've tried various versions of FES / MES and 3 different laptops running xp, win7 and win 8.1 and they all do the same.

The elm 327 cable needs modifications to connect to abs and airbag modules of the car because Croma modules for these systems are on a different pin of the obd2 than standard for the other cars so there is no communication. A dip switch installed is needed if the cable is to be used for various cars or resoldering only is the cable will be for Croma only. It been a long time so I don't remember specifics but I believe there is an explanation of various cables and needed alternations on the Multiscan site.

This page explains it all: http://www.multiecuscan.net/SupportedVehiclesList.aspx

For ABS Pin 7 has to be connected to Pin 1.

Strongly suggest you get these: http://www.gendan.co.uk/product_FESCBL.html

or you can get each one separately I believe.

In addition Brian

As you say it won't connect to anything else then much of the "else" on the Croma is on CAN Bus.

I'm suspecting you have one of the cheap Chinese ELM devices that have CAN line resistor termination issues.

You need to read this long, long thread here: http://forum.multiecuscan.net/viewtopic.php?f=5&t=1493