Join Date: Nov 2014
Location: Scotland, UK.
Drives : Nissan NV200
Flies : Rans S6ES
Mentioned: 113 Post(s)
Quoted: 2335 Post(s)
You would really need to remove the tailgate trim and check to see if there is a power supply and earth at the tailgate actuator when the doors are locked/unlocked.
If the power & earth are good you know the actuator has failed and will need replaced. If not, you probably have a broken wire.
The wiring often breaks where it routes between the car body and the tailgate. I'm sure there are already a couple of threads about broken wires in the loom there.
It wont fail the MOT because of this fault.