door locking system

Mercedes » E-Class » 1996-2003
Problem Description

e200 est 2001 central locking not working at all i have to manually lock all doors internal switch not locking key fob flashes as do indicators when fob is pressed alarm system not working either i have changed unit under rear seat with all the pipes on still nothing is there a control unit or relay and where are they? right hand drive
many thanks
DENNIS