Thank you Rod...
Ok you have the one I thought it seems - there were different systems depending in exact date of build.
This Im afraid, as you may have guessed, is not going to be simple.. It basically is usually either failure of the actual buzzer unit, or the controlling chips... BUT, first Rod - check to see if your interior light comes on when you open the drivers door. If it doesn't - and its set right, then you most likely just have a faulty switch there - on the door post. These are cheap to replace or can often be cleaned up by removal / clean... So if you have that issue - try a clean first... and then renew if no good still.
If its not that issue Rod, then its a "computer" fault basically.. I wil give you a pic below to show you / give you an idea / better idea of what Im on about - and where the buzzer is.. etc.
If its looking like this is the issue Rod - the above door switch ruled out - then I would suggest contact this company on 0 7 5 2 7 - 8 7 7 9 9 5 These units cannot be just changed over because they have the programming for the central locking / immobiliser all in there... so you have to have either your unit repaired - or, a replacement unit, coded to your fobs for the car to start etc after replacement. They will talk you through it inc costs etc.
So those are the ways forward on this Rod - Im really sorry its not an easy fix - other than the door switch of course - but you have all the info you need now..
Let me know how you get on - or if you need anything else at all...
Kind Rgds - MIKE.
...Meantime..............Please do click on the "OK/ Excellent ratings"
for me as that's how Im credited for helping you - Thank you in advance for that
You can and are most welcome to get back to me anytime you might need - clicking the OK ratings does not close you out at all..