Description and principle of operation (Defender 2007+)

Central door locking (CDL) - from 2002 model year

Central Door Locking (CDL) is a new feature for the 2002 Defender.

Note: CDL applies to all doors on station wagons and County station wagons. On all other variants of the Defender 2002 model year, CDL only affects the driver's doors and the front and rear passengers.

CDL affects all doors including the tailgate and is controlled by pressing the appropriate button on the remote control, turning the vehicle key in the driver's door lock, or by using the locking button on the driver's door.

The CDL system actuates the latches (with electric drive) on the doors, which are controlled by the anti-theft alarm ECU located behind the instrument panel. The anti-theft alarm ECU receives constant electrical power from fuse 6 located in the passenger compartment fuse box. Each CDL latch motor is connected by two wires to the anti-theft alarm ECU, which alternately supplies power and provides ground to drive each motor to the lock or unlock positions.

If the latch motors operate continuously for a short period of time, the theft deterrent ECU will delay the operation of all CDL latch motors for 15 seconds to prevent the motors from overheating. But before suspending the operation, the theft deterrent ECU must ensure that all doors are in the unlocked state.



If the vehicle is locked and the key is in the ignition switch, or the ignition is on and the anti-theft alarm ECU inertia switch is triggered, all doors are immediately unlocked and the hazard warning lights are activated. To prevent accidental re-locking, all latch motors are locked and remain locked until the anti-theft alarm ECU "senses" that the driver's door is opened with the key removed from the ignition switch.

Locking the vehicle using the remote control is disabled when the key is in the ignition switch.

Locking when the door is slammed

With the introduction of the CDL system, the driver's door locking function when slamming is eliminated. When an attempt is made to slam the car door, the anti-theft alarm ECU unlocks all the doors.

CDL control via locking button on driver's door

Each door has a locking button that allows you to individually lock a specific door from inside the car. The locking button on the driver's door has an additional function that allows you to lock all doors from inside the car using this button.

When the driver's door lock button is pressed, the CDL system enters a locking state in which all doors are locked but the immobilizer and perimeter and volumetric anti-theft sensors are disabled. The CDL mode using the driver's door lock button can be activated with or without the key in the ignition switch and without the ignition on.

When the CDL system is in the lock button lock mode and the lock button on the remote control is pressed, the volumetric and perimeter components of the anti-theft alarm system and the engine immobilizer are activated.

CDL control with a key

The driver and front passenger doors are equipped with cylinder locks. Turning the vehicle key in the passenger door locks or unlocks only that specific door. Turning the key in the driver's door operates the CDL system and unlocks or locks all doors.

NOTE: The passenger door lock cylinder is connected to the door latch and has no electrical connection to the anti-theft alarm ECU. The driver door lock cylinder is also connected to the door latch and its operation is controlled by the ECU only via the latch motor and two wires connected to it.

When the vehicle is locked with the key through the driver's door, only the CDL and perimeter security functions are activated. The volumetric security and active immobilizer are not activated.

Controlling CDL with Remote Control

The remote control has two buttons - locking and unlocking. One press of the locking button causes locking of all doors and activates functions of perimeter and volumetric protection and active immobilizer. Locking from the remote control is blocked if the transponder coil "feels" that the key is in the ignition switch.

When the vehicle is locked, a single press of the unlock button unlocks all doors and disarms perimeter and volumetric protection. The immobilizer is only disarmed by using the transponder coil and remote control or performing the EKA procedure.

Anti-theft system LED

In addition to the status signals of the anti-theft alarm system, the corresponding LED also shows the status of the CDL system.



The system confirms that the driver's door is open by turning on the LED for 10 seconds (confirmation period). If another door or the bonnet is opened, the LED remains off for a 10 second confirmation period. After the 10 second confirmation period, if the alarm is armed, the LED returns to a slow warning flash.

Interior lighting functionality

The anti-theft alarm ECU controls the interior lighting functionality. When the lamps go out, they gradually transition to the "off" state over a 2-second period.

Lighting turns on:

• When disabling the alarm using the remote control,
• When opening any door.

When the light is on, it will dim as a result of the following actions:

• If all doors are closed, the lights will turn off after a 15 second delay.
• If any door remains open, the lighting will go out after an 8-minute delay.
• If one of the above delay periods is in effect and the ignition is switched on or the alarm is activated, the lighting will go out.