Doors lock and unlock at random whilst car is in motion

[Yorkshire Engineer]

Slight bumps in road causes central locking to randomly lock or unlock doors.
One Possible cause: Worn out boot lid cable harness on saloon models. Insulation failing causing cores to touch.
Verification: temporarily unplug boot lid harness from remainder of fixed harness. Connector located under parcel shelf on near side of car. If problem goes away then boot lid harness needs replacing. Moderately easy to do.
Applies to: Saloon cars. Similar problem could apply to hatchbacks.