Power Locks: Description and Operation

WITHOUT KEYLESS ENTRY
When a Door Lock Switch is activated in the Power Door Locks System, all doors lock or unlock in unison. Each lock can also be operated manually from the locking knob. The locks are operated by reversible actuators that receive voltage from two relays in the Door Lock Relay. These relays operate to turn the actuators on by applying a voltage to one of the terminals and a ground to the other terminal. To reverse the actuators, the polarity to the terminals must be reversed.

When either Door Lock Switch is moved to the "LOCK" position, it completes a circuit to the coil of the Door Lock Relay. The Door Lock Relay is energized. Its contact for the Lock Relay closes and is connected to battery voltage through CKT 1540, which is the voltage feed for driving the actuators.

Voltage is then applied to CKT 295 and to the Door Lock Actuators, which are grounded by CKT 294 from the other terminal of the motor through the contact for the Unlock Relay. The actuator in each door runs to operate the door lock. When the Door Lock Switch is released, the Lock Relay contact closes to ground again and the actuators turn off.

A similar action occurs with the Door Lock Relay when it is energized by either of the Door Lock Switches closing to the "UNLOCK" position. Now CKT 294 to the actuators carries battery voltage and CKT 295 is grounded. The polarity of the voltage to the actuators has reversed. The actuators run in the opposite direction to unlock the doors.

The Door Lock Switches are usually closed for just a moment. If they are held closed, a circuit breaker in each actuator will open to protect against damage. The circuit breaker resets only after voltage is removed from the actuator.

WITH KEYLESS ENTRY
All Door Locks operate the same as without Keyless Entry except the LH Door Lock. When either Door Lock Switch is moved to the "LOCK" position, the Door Lock Relay is energized and voltage is applied to the GRY wire and to the Door Lock Actuators. The LH Front Door Actuator is grounded through the Remote Door Lock Control Receiver C2 terminal "F". The other Door Lock Actuators are grounded through the normally open contacts of the Unlock Relay. When either Door Lock Switch is moved to the "UNLOCK" position, voltage is applied to C1 terminal "E" of the Remote Door Lock Control Receiver. This is the Unlock Enable signal that tells the Remote Door Lock Control Receiver to energize C2 terminal "D", which then applies voltage to CKT 294 and to the LH Front Door Lock Actuator. The LH Front Door Lock Actuator is then grounded through the normally open Lock Relay contacts of the Door Lock Relay.