General Information

When a door lock switch is activated in the power door lock system, all of the 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 the Body Control Module (MALL). These relays operate to turn the actuators on by applying voltage to one terminal and ground to the other terminal.

When either door lock switch is moved to the LOCK position, it completes the circuit to the Body Control Module (MALL). The MALL Module then applies voltage and ground to the door lock actuators. The actuator in each door runs to operate the door locks.

A similar action occurs when the door switches are moved to the UNLOCK position. The voltage polarity to the actuators reverses and 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, an electronic circuit breaker in each actuator opens to protect against damage. The circuit breakers have positive temperature coefficients (PTC) and reset automatically when voltage is removed from the actuator.