Mercedes central locking pump failing

Mercedes central locking pump failing

The vacuum / pressure pump can fail on certain larger Mercs, typically the S Class. The pump
also operates other comfort features such as lumbar support, boot open and close assist, headrest
lowering etc.

Other items to check in the system are the actuators. These work in two directions, but may only
hold vacuum in one of those directions. Also check the seals around the pipes where they join
the resovoir.