Door Lock/Unlock Actuator Circuits

The reversible actuators control the power door locks. The power door electrical system controls the actuators by applying battery voltage to 1 terminal and ground to the other terminal. The body control module (MALL) supplies this battery voltage and ground when the module receives an input signal from a front power door lock switch. Normally, the MALL module connector C1 terminals A and C are both at ground. The MALL module control at connector C1 terminal C switches to battery voltage in order to lock the doors. The module provides battery voltage to all of the actuators on CKT 295 (GRY). The opposite side of each actuator is connected on CKT 294 (TAN) to the MALL module connector C1 terminal A. The MALL module connector C1 terminal A is still at ground. The actuator in each door runs in order to move the door locks to the LOCK position. The MALL accomplishes the unlock function in the same way. However, for unlock the MALL provides battery voltage on CKT 294 (TAN) while holding CKT 295 (GRY) at ground. The door lock actuators are usually powered for just a moment. If the door lock actuators remain on, an electronic circuit breaker in each actuator opens in order to protect against damage. Each circuit breaker has a positive temperature coefficient (PTC) which resets automatically when voltage is removed from the actuator.