Yes,
That would do it.
The vacuum is not connected to the ABS CM but is connected to the cruise control actuator and as there is a request input for cruise activation but no vacuum supply, the vehicle monitoring realises there is a problem and just "hunts" for the nearest solution.
In this case it came up with a communications error code indicating the ABS CM, not illogical when you think about it.
Thanks go to Dave Marks,i hope he doesn't mind me posting the above reply to my question.
Graham
