i thought i would provide an update in case it helps others with same issue.
I booked into local ford dealer garage,,,,,they could not find what was wrong.
The following day I took it for a 280 mile drive without stopping and i got the same message "steering assist malfunction".....I restarted the car several times and still got the same message,,,,,with heavy steering I drove the car for about half a mile and parked in safe place.
I contacted the garage that sold me the car (was about 5 miles away). They sent out AA (covered by Ford as car was under 12 months old). AA couldn't do anything and so the car was being taken back to the Ford dealership that sold me the car. We got there just before 6pm and so the staff in garage had gone and no one could do anything until Saturday. In the mean time a courtesy card had been arranged via Ford for me to use. On saturday I was told by the garage that the steering rack needs replacing.....they had ordered it on Saturday....but it won't be fitted until Monday morning. I picked up my repaired car on Monday and drove 280 miles back to glasgow (without stopping)....when I got home, the steering malfunction light did not appear.....so hopefully its all sorted now.
Its just odd that the steering rack needed replacing on an 8 month old car that had only done just under 3k miles.