With intermittent faults like this, one way of approaching the problem is to try and simulate the cause, i.e. you know that vibration can activate the door open warning light. So you need to make the CCU ( Central Control Unit) think that all doors are shut but be able to agitate the lock / internal door cable.
First step is to get to a state where the door open warning light is off with all doors closed. Step two is to start with the drivers door. With it open, trip the lock with a shaft of a screw driver. The door open light should go out. If not try agitating the wiring in the harness between door and pillar (you may need to remove the door card to gain access). If the light is still on, try moving the cabling inside the door, or wiggle the plug connecting the cable to the lock. If no fault is found, try tapping the door frame next to the lock in case the lock micro switch is faulty. When you have finished checking that door, RELEASE THE LOCK BY PULLING THE DOOR OPEN HANDLE AND PULLING THE SCREWDRIVER BLADE OUT WARDS. Failure to do this will result in lock damage if you try and shut the door! Repeat this check on all doors. Don't forget the switch under the bonnet. Good Luck - Eric.