Electrical Diagrams

Central Locking Diagrams:

Central Locking Components:

Locations of components

22 Fuse box
In the electrical distribution box in the engine compartment, on the left-hand wheel housing

57 3-pole connector
One in the left-hand front door
One in the engine compartment, at the upper hinge of the left-hand front door, behind the electrical distribution box

57R 3-pole connector
One in the right-hand front door
One in the engine compartment, at the upper hinge of the right-hand front door

59 2-pole connector
One in the right-hand front door
One in the engine compartment, at the upper hinge of the right-hand front door
One in the left-hand rear door
One in the right-hand rear door
One in the luggage compartment lid, near the motor for the luggage compartment lock
One in the luggage compartment, above the left-hand wheel housing

59R 2-pole connector
One in the left-hand front door
One in the engine compartment, at the upper hinge of the left-hand front door, behind the electrical distribution box

65 Earthing point
At the handbrake

123 4-pole connector
One in the left-hand B pillar
One in the right-hand B pillar

152A 29-pole white connector
In the electrical distribution box in the engine compartment, on the left-hand wheel housing. The connector is accessible from the interior of the car

158 Negative distribution terminal
In the electrical distribution box in the engine compartment, on the left-hand wheel housing

175 Electronic unit for the central locking system
Under the facia on the right-hand side, behind the knee shield

183 Control unit for the driver's central door lock
In the driver's door

184 Motor for the co-driver's door lock
In the co-driver's door, at the rear

185 Motor for the right-hand rear door lock
Under the lock in the right-hand rear door

186 Motor for the left-hand rear door lock
Under the lock in the left-hand rear door

188 Motor for the tailgate lock
In the tailgate

Operation
The central locking system of the car locks or unlocks all doors and the luggage compartment lid when the key is turned in the lock of the driver's door.

Terminal 4 of electronic unit 175 for the central locking system is continuously supplied from fuse 24, via the 29-pole white connector 152A. The electronic unit is controlled by control unit 183, which is mounted in the driver's door.

When the driver's door is locked, terminal 1 of the electronic unit will be earthed across the control unit to negative distribution terminal 158. Current will then flow from output 8. All central locking motors (which are connected in parallel) will now be energized for approx. 1 second and the doors will lock. The motors are earthed through pin 7 of the electronic unit, and on from terminal 3 to earthing point 65.

When the driver's door is unlocked, terminal 2 of the electronic unit will instead be earthed across the control unit. The motors will now be energized from pin 7 instead, and will be earthed across pin 8 of the electronic unit (for approx. 1 second), causing the locks to open.

On right-hand drive cars, the control unit is connected to connector 57R, and motor 184 for the co-driver's door lock is connected to connector 59R.

Fault-tracing hints
1. Check fuse 24 and check that the supply to it is live.

2. Check that the supply to terminal 4 of electronic unit 175 is live.

3. Check that pin 7 of the electronic unit is live when the doors are being unlocked and that pin 8 is live when the doors are being locked.

Note that terminals 7 and 8 are energized for only around one second in conjunction with locking and unlocking. Measurement at these terminals must therefore be carried out when control unit 183 is switching over.

4. Check the connectors, cable harnesses and earth connections.

Note: On testing, the actuating motors may be connected to terminals 7 and 8 of the electronic unit only. Do not connect them to any other power supply sources. Doing so may overload the motors and damage them.