Door Lock System Components
The power door lock system consists of the following components:
| • | Left front door lock switch |
| • | Right front door lock switch |
| • | Endgate/liftgate lock cylinder switch (utilities only) |
| • | Driver door unlock relay |
| • | Body Control Module (BCM) |
| • | Reversible door lock actuators in each of the doors |
| • | MIR/LOCK 3A fuse (switch supply voltage) |
| • | PWR LKS15A fuse (relay supply voltage) |
Door Lock System Controls
The power door lock system can be controlled by any of the following:
| • | A power door lock or unlock switch activation |
| • | A keyless entry transmission, if equipped |
| • | An automatic door lock or unlock function |
Driver and Passenger Door Lock Operation
When any of the door lock switches are placed in the lock position,
voltage is applied to the door lock control circuit and the lock relay winding.
Since the other side of the lock relay winding is connected to ground,
the relay is energized. This causes the contacts to close and complete
the path from the PWR LKS fuse through the battery voltage circuit.
Voltage is then applied to the lock side of the door lock actuators.
Since the other side of the passenger door lock actuator(s) are connected
to the normally closed contacts of the unlock relay to ground and
the driver door lock actuator is connected to the normally closed contacts
of the driver door unlock relay to ground, the doors lock.
The lock function can also be accomplished by the BCM supplying voltage
to the door lock control circuit by any of the following:
| • | A keyless entry lock transmission |
| • | An automatic door lock function |
Driver Door Unlock Operation
The driver door unlock control circuit uses a dedicated driver door
unlock relay. This is done so that the driver door may be unlocked by itself
using a keyless entry unlock transmission. The driver door unlock
relay differs slightly from the unlock relay in that the coil side
of the relay is connected to the PWR LKS fuse and the door unlock control
circuit is pulled to ground by the BCM to energize the relay.
When any of the door lock switches are placed in the unlock position,
a voltage is applied to the unlock relay and to the BCM. When the BCM senses
the voltage signal, it grounds the driver door unlock control circuit.
Since the other side of the driver door unlock relay winding is connected
to the PWR LKS fuse through the battery voltage circuit, the relay is
energized. This causes the contacts to close and complete the path
from the PWR LKS fuse through the battery voltage circuit. Voltage is
then applied to the unlock side of the driver door lock actuator.
Since the other side of the driver door lock actuator is connected
to the normally closed contacts of the lock relay to ground, the driver
door unlocks.
The unlock function can also be accomplished by the BCM supplying voltage
to the door lock control circuit during a keyless entry unlock transmission.
Passenger Door Unlock Operation
When any of the door lock switches are placed in the unlock position,
voltage is applied to the door unlock control circuit. The door unlock control
circuit supplies voltage to the unlock relay winding and the BCM. Since
the other side of the unlock relay winding is connected to battery voltage,
the relay is energized. This causes the contacts to close and complete
the path from the PWR LKS fuse through the battery voltage circuit.
Voltage is then applied to the unlock side of the door lock actuators.
Since the other side of the passenger(s) door lock actuators are connected
to the normally closed contacts of the lock relay to ground, the doors
unlock.
The unlock function can also be accomplished by the BCM supplying voltage
to the door lock control circuit during a keyless entry unlock transmission.
Lockout Prevention
This feature prevents the locking of the driver door if the ignition
key is left in the ignition lock cylinder. If a lock function occurs from
any door lock switch and the BCM senses an active state on either
the left front door latch signal, secondary door latch switch signal
and/or the lift gate ajar switch signal circuits and the key in ignition
switch signal circuit is in the yes state, the BCM will cycle the
door lock relay to lock the doors and then cycle the driver door unlock
relay to unlock the driver door.
Programmable Automatic Door Locks
Vehicles equipped with the automatic door lock option are factory programmed
to have the automatic door lock feature lock all the doors when the following
conditions are met:
| • | Ignition 1 input is active. |
| • | All door jamb switch inputs are inactive |
| • | Lift gate / lift glass adjar inputs are inactive. |
| • | Vehicle speed is greater than 15 mph (24 km/h)
for 2 seconds. |
This automatic door lock function will only occur once per ignition
cycle unless, any door jamb switch input changes state to active and back
to inactive. Then the automatic door lock feature will lock all doors
again.
Once the automatic door lock feature has locked the doors, the automatic
door lock feature will then unlock all the doors once the ignition key is
removed from the ignition.
For detailed instructions on programming the automatic door locks, refer
to
Vehicle Personalization
in Personalization.
