For 1990-2009 cars

The battery voltage applies at all times through the door lock fuse to the power door lock control module. The control module for the door lock grounds at G203.

Pressing either of the power door lock switches to the UNLOCK position, the control module receives a ground at the UNLOCK INPUT terminal. After applying the ground signal, the control module applies voltage to the UNLOCK OUTPUT terminal and applies a ground to the LOCK OUTPUT terminal.

With power and with ground that is applied to the door lock motors in the power door lock actuators, the power door lock motors turn. This moves the mechanical linkages in the doors that unlock the doors.

Pressing either of the power door lock switches to the LOCK position, the control module receives a ground signal at the LOCK INPUT terminal. After applying the ground signal, the control module applies a voltage to the LOCK OUTPUT terminal.The control module applies a ground to the UNLOCK OUTPUT terminal.

Applying power and ground to the power door lock motors in the power door lock actuators, the power door lock motors turn. This moves the mechanical linkages in the doors that unlock the doors.