Central locking on w210

Sorry Andrew , no BCM on this vehicle . The Central Security Module is incharge of power door locks . Central Security Module For additional information, refer to Section 419-10 .
The central security module is equipped with a battery back-up which holds the programmed transmitter(s) memory in the event of the vehicle battery disconnection.
Principles of Operations The Door Switch Lock Function When a door lock switch is moved into the lock position or a door lock cylinder is rotated to the lock position, the door lock switch grounds the lock circuit input to the central security module. The central security module then provides 12 volts to one side of the door lock actuators contained in the door latch unit and simultaneously grounds the other side of the door lock actuators. This completes the door lock actuator circuit, causing the door lock actuators to rotate a cam assembly, which then locks the doors.

The Door Switch Unlock Function When a door lock switch is moved into the unlock position, the door lock switch grounds the unlock circuit input to the central security module. The central security module then provides 12 volts to the opposite side (relative to locking the door) of the door lock actuator(s) contained in the door latch unit and simultaneously grounds the other side of the door lock actuator(s). This completes the door lock actuator circuit, causing the door lock actuator(s) to rotate a cam assembly in the opposite direction, which then unlocks the door(s). The 12 volts which the central security module provides to the door lock actuator(s) are provided to each door lock actuator from the individual pins on the central security module connector.

Keyless Entry When a remote transmitter button is depressed, it transmits the appropriate command to the central security module as a radio frequency. The central security module receives the command from the remote transmitter through an antenna, which is incorporated in the central security module.
When the central security module receives a command from the remote transmitter, it then sends the appropriate output to control the desired devices. These outputs devices include:

• The front and rear door lock units.
• Central timer module (CTM).
• The liftgate release motor.
• The right and left side turn signal lamp(s).

The central security module sends a signal to the CTM when courtesy lamp illumination is required.
Computer Operated Locks Each front door lock actuator contains a bipolar motor that controls the lock and unlock linkage. The lock/unlock lever of both front door interior handles use linkage to actuate the lever lock switch located inside each front door lock actuator. Each lever lock switch remains in the unlock position until lock/unlock lever of the interior door handle is moved to the lock position. This action toggles the lever lock switch to the lock position. The central security module uses only one electrical input for both lever lock switches. The central security module cannot determine whether the driver or passenger door lever lock switch was actuated. Therefore, actuating the lock feature from either front door will have the same affect of locking all doors. Actuating the unlock feature will not unlock any other door.
The door lock control switches for both front doors also use only one input to the central security module.
Both rear passenger doors contain a rear door lock actuator that controls only electric lock or unlock of the door. Actuating the lock/unlock lever at either rear passenger door will have no effect on other doors.
The panic feature of the remote transmitter sounds the vehicle horn when the vehicle is not equipped with anti-theft. If the vehicle is equipped with anti-theft feature, a separate horn is sounds for the panic feature.

Does it have keyless entry ?
Power Door Locks
The central security module controls the power door lock and keyless entry system. The lock and unlock operation is carried out by supplying ground to the central security module from the door lock control switch. The normal path of the actuators is to ground through the central security module. The door lock control switch will lock and unlock all doors by grounding the appropriate circuit to the central security module. The central security module then supplies power to the appropriate common actuator circuit to lock or unlock all doors.

Keyless Entry
The keyless entry remote transmitter sends a frequency that is received by the central security module internal antenna. Depending on the frequency received, the central security module will lock all doors or unlock the driver door. If the unlock frequency is received again within five seconds of the first unlock, the central security module will unlock all doors.
If the frequency received is from the panic button, the central security module will cycle ground to the parking lamps and horn. The parking lamps and horn will continue to cycle until the panic button is pressed again or the ignition switch is turned to the RUN position.

Check fuses, remote control battery, try to push "unlock" button 5 or more times. If it won´t help, you need Tech-2 diagnostics.

usually in the boot on mercs mate

try takeing the door panel off and check to see if the rod came out of the lock button.

I had a problem where my key fob did not lock or unlock the car, Renault Clio Dynamique, but the central locking button in the car did still work and engine turned over fine. Changed the key fob battery still nothing. Read online about disconnecting and reconnecting the car battery, (negative only) and hey presto it worked! All working fine now!

Check these fuses again:
In the Power Distribution Center (in the engine compartment, left fender panel) Fuse #3 (20 Amp) Fuse #7 (40 Amp), Fuse #12 (20 Amp) and in the Junction Block (on the left end of the dash) Fuse #1 (15 Amp)
Use a test lamp and make sure that these fuses have power. All of these fuses should all have power at all times, regardless of ignition switch position. If they are all good and have power, then you probably need to replace your Central Timer Module. All of the circuits you listed are dependant on this module for operation.

The Central Timer Module is located at the left kick panel.

Central Timer Module System

The CTM is available in a BASE or a HIGHLINE configuration. The BASE and HIGHLINE CTM provide the following features:
• Battery saver functions for exterior and interior lights
• Cargo lamps chime warning
• Courtesy lamps
• Dome lamps
• Dome lamp defeat
• Door ajar switch state
• Fog lamps
• Headlamp time delay
• Intermittent wiper controls
• Low and high beam head lamps
• Optical horn
• Park lamps

In addition, the HIGHLINE CTM provides the following features:

• Central locking
• Door lock inhibit
• Driver door unlock
• Enhanced accident response
• Horn chirp
• Optical chirp
• Power door locks
• Remote keyless entry (VTSS)
• Remote radio

I'm having the same problem have you fixed yours?

Hi steve,try the central locking fuse,fuse 63.its in a stupid place (thanks ford)its at the back of fuse panel.two bolts release the fuse board,turn it around and there it sits,20 amp fuse.replaced mine and its working great.hope this helps mate