Land Rover Repair: DOOR LOCK, latch mechanisms, becm

Question
Why is the warning light on the dash board indicating that there is a door open when all the doors are locked ?
The central locking is still working but making a noise of a horn when activated.

Please advise

Answer
It's making the horn noise to signal a mislock.  It thinks a door is open.  If all your doors are shut, then the switch in one of them is bad, and the body computer is thinking it's open.

A shop with the special Land Rover test system can talk to the BECM and see which door is the culprit.

In most cases, the switches are part of the latch mechanisms, and they cost a couple hundred dollars, and take a few hours to change.