Locks: Description and Operation

CENTRAL LOCKING

CIRCUIT OPERATION

The Central Locking System is controlled by the Central Locking Control Unit. This unit senses when a lock switch is moved by a key, and sends the appropriate signal to drive the motors. The Central Locking Control Unit controls the Door Locks, Gas Filler Lock and Trunk Lock. The unit also has an Inertia Switch which closes on impact greater than 5g. If Ignition Switch is in RUN or START, the locks are then unlocked.

Lock
When the key is inserted into a lock and turned clockwise, the lock switch moves to LOCK and grounds terminal 7 of the Central Locking Control Unit. The unit then activates the Lock Relay and applies voltage from the Fuse to the Lock Motor, which is grounded through the Central Locking Control Unit, terminal 2. The Lock Motor then pulls the Safety Catch Button. As the motor runs, a switch is moved from terminal 2 to terminal 6 of all the motors except the Driver's Lock Motor. At terminal 6, the switch position breaks the current flow from the Central Locking Unit Control Unit.

Unlock
When the key is turned counterclockwise, terminal 6 of the Central Locking Control Unit is grounded through the lock switch. The Central Locking Control Unit then activates the Unlock Relay and applies voltage from the Fuse through terminal 2 to the Lock Motor. The motor is grounded through the Central Locking Control Unit, terminal 1. The polarity is reversed and the motor pushes the Safety Catch Button lock up.

Unlock Inhibit
When the key is inserted into the driver's lock and turned clockwise past the LOCK position, the Unlock Inhibit mechanism is engaged. This mechanically inserts a bar into the driver's lock and prevents unlocking through use of the Safety Catch Button. When in the UNLOCK INHIBIT, the Central Locking Control Unit is grounded at terminal 10. The unit then activates the Lock Relay and voltage is now applied to the motors through the Unlock Inhibit Switch and wires to terminal 6 of the motor. The motors are again activated and engage their Unlock Inhibit mechanisms.

Trunk Lock
The Trunk Lock operates in a manner similar to the door locks.