Mercedes-Benz W220 central locking, tailgate and soft-close doors not working: PSE pump and fuse
W220 central locking, tailgate and soft-close doors all stop working at once: what is wrong?
Most likely the PSE pump (the vacuum pump that moves the locks) is not getting power or is faulty. First check its 20 A fuse no. 62 and the condition of the battery. The fuse also cuts power to other air-operated functions, such as the seat supports.
Why does the PSE pump fuse blow again or the pump fail?
The pump can run too long if there is a leak in the vacuum line. Then the fuse blows or the pump overheats and fails. The pump's timeout stops it also because of a hose leak. Just replacing the fuse is therefore not always enough.
W220: the PSE pump drains the battery, what causes it?
The pump can receive a continuous command if the valve control is stuck or vacuum is leaking. The battery can also be drained by a short-circuited switch in the tailgate opening handle. If the pump is replaced, the fault can go away.
W220: the tailgate hydraulic pump gets no power, where do I start?
The suspects are the rear control unit, the wiring, the fuse and the pump. Measure the voltage at the pump connector from pins 2 and 6 and run the checks with the guided tests of the Mercedes-Benz diagnostic tool.