Power Door Locks Description and Operation

Door Lock System Components The power door lock system consists of the following components: Driver door lock switch Passenger door lock switch Left rear door lock switch Right rear door lock switch Driver front side door window control switch Passenger front side door window switch Driver front side door latch Passenger front side door latch Left rear side door latch Right rear side door latch Exterior door handle switches Body control module Lighting control module Door Lock System Controls The power door lock system can be controlled by any of the following: Power door lock switch activation Keyless entry lock or unlock command Delayed locking command Automatic door lock command When the OnStar® system is used to unlock the driver door Door Lock and Unlock Operation The driver or passenger front side door window control switch will monitor the voltage of their respective door lock switches, when the driver or passenger door lock switch is activated in the lock or unlock position the signal voltage will be pulled low, the corresponding front side door window control switch will detect the voltage drop in the signal circuit and will send a serial data message to the body control module requesting the door lock or unlock command. The lighting control module will monitor the voltage of the left rear and right rear door lock switches, when the left rear or right rear door lock switch is activated in the lock or unlock position the signal voltage will be pulled low, the lighting control module will detect the voltage drop in the signal circuit and will send a serial data message to the body control module requesting the door lock or unlock command. The body control module upon receipt of a lock or unlock request, will supply battery voltage to the door lock actuator lock or unlock control circuits. Since the opposite side of the lock actuator is connected to ground through the other lock actuator control circuit, the doors, and fuel filler door will then lock or unlock as commanded. The following control circuits are used to operate the door lock actuators: Driver door unlock only Passenger and rear door unlock All door lock This sequence and be modified through the personalization settings Passive Door Lock/Unlock Operation The exterior door handle switch signal circuits provide inputs to the body control module when the exterior door handle switches are activated. These inputs allow the body control module to detect a door lock or a door unlock request. The body control module provides a 7 V signal to each exterior door handle switch via the door handle switch signal circuits. When a door handle switch is pressed, the switch closes and the voltage signal within the signal circuit is pulled to ground. The body control module will detect the voltage drop and a low frequency antenna will transmit a challenge to the keyless entry transmitter. If the challenge is met, the keyless entry transmitter will respond, and the body control module will command the door(s) to be locked or unlocked