Driver and Passenger Door Unlock Operation

When any of the door lock switches is pressed to the unlock position, the BCM door lock/unlock signal circuit changes from an idle voltage of 3.4 volts to 1.7 volts generating an unlock command. The BCM then applies battery positive voltage to the Door Unlock Relay and the Driver Door Unlock Relay when equipped with keyless entry, the relay(s) in turn apply battery positive voltage to the Door Lock Actuator unlock circuit of all the Door Lock Actuators. Since the Door Lock Actuator lock circuits are held to ground through the resting Door Lock Relay, the actuators execute the unlock command, unlocking the doors.

The unlock function can also be accomplished by the BCM having received a keyless entry door unlock command, if the vehicle is equipped with keyless entry. keyless entry personalization allows the driver door to be unlocked individually before unlocking the passenger doors. When this feature is active, the BCM will require a repeated unlock command to unlock the passenger doors.