Door Lock System Components
The power door lock system consists of the following components:
|     •  | Liftgate lock/unlock release switch, if equipped | 
 
|     •  | Driver door unlock relay, w/ keyless entry | 
 
|     •  | Body Control Module (BCM) | 
 
|     •  | Reversible door lock actuators in each of the front doors | 
 
|     •  | Reversible door lock actuator in the side door | 
 
|     •  | Reversible door lock actuator in the cargo door or liftgate | 
 
|     •  | CIG LTR 20A fuse (switch supply voltage) | 
 
|     •  | PWR ACCY 30A circuit breaker (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 | 
 
|     •  | A BCM delay lock function | 
 
|     •  | A BCM lockout prevention function | 
 
Driver and Passenger Door Lock Operation - w/o Keyless Entry
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 ACCY circuit breaker through the battery voltage
  circuit.  Voltage   is then applied to the lock side of the door lock actuators.
  Since  the other   side of the all the door lock actuators are connected
 to  the normally  closed   contacts of the 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 a delay lock function.
Driver and Passenger Door Lock Operation - w/ Keyless Entry
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 ACCY circuit breaker 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, cargo door
or sliding side   lock actuators  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 | 
 
Driver and Passenger Door Unlock Operation - w/o Keyless Entry
When any of the door lock switches are placed in the unlock position,
  voltage is applied to the door unlock control circuit and the unlock relay
      winding. Since the other side of the unlock relay  winding is connected
    to  ground, the relay is energized. This causes the contacts to close
and     complete  the path from the  PWR ACCY circuit breaker through the
battery     voltage circuit.  Voltage is then applied to the unlock side of
the door    lock  actuators. Since  the other side of the door lock actuators
are connected     to the normally closed  contacts of the lock relay to ground,
the doors   unlock.
Passenger Door Unlock Operation - w/ Keyless Entry
When any of the door lock switches are placed in the unlock position,
  voltage is applied to the door unlock control circuit and the unlock relay
      winding. Since the other side of the unlock relay  winding is connected
    to  ground, the relay is energized. This causes the contacts to close
and     complete  the path from the PWR ACCY circuit breaker 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 by a keyless entry unlock transmission.
Driver Door Unlock Operation - w/ Keyless Entry
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 primary side of the
  relay  is connected   to the PWR ACCY circuit breaker and the door unlock
  control  circuit is pulled   low 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 ACCY circuit breaker  through the battery voltage circuit,
 the  relay   is  energized. This causes the contacts to close and complete
 the  path from   the  PWR ACCY circuit breaker 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.
Liftgate Lock/Unlock Release Switch Operation
 On vehicles equipped with a liftglass and dutch doors, the liftgate
  lock/unlock release switch (mechanical key)  is added  to serve the same
 function   as the front   power door lock switches. By inserting the door
 key into the   liftgate lock/unlock   release switch and turning the key
to  the lock or  unlock  positions, voltage   is applied to the door lock
or unlock  control  circuits  to control the lock   or unlock relays. This
will lock  or unlock  all of the  doors, including the dutch doors. Once the
door lock  system is  unlocked, press  the liftgate release   switch to electrically
 open the liftglass  and pull  the handle to open  the   secondary latch.
For further information about the liftgate release system, refer to 
Rear Hatch/Gate Description and Operation 
  in Body
 Rear End.
Delay Locking Operation
This feature allows the operator to lock all the doors from any door
  lock switch or a keyless entry lock transmission with the side door open.
   The sliding side door has contact plates   that complete the power door
 lock   and unlock fuse supply circuits when the sliding side door is closed,
 and   interrupt these circuits  when the  sliding side door is open. When
 a lock   function occurs and the BCM  senses  an active state on the sliding
 side  door  ajar switch signal circuit (door  open),  the driver, passenger
  and  cargo doors will lock as described, and  the BCM   continues to monitor
  the   sliding side door ajar switch signal circuit  .  When the BCM senses
  an  inactive state (door closed), the BCM will cycle  the  door lock relay
  again  after approximately 5 seconds to perform another  lock  function,
 thus  locking  the sliding side door.
Lockout Prevention Operation
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
The automatic door lock feature can be programmed to control the door
 lock system. The automatic door lock feature is factory programmed to have
 all doors lock and unlock. For detailed instructions on programming the automatic
 door locks, refer to 
Vehicle Personalization 
 in Personalization.
When the automatic door lock feature is programmed to control
the door  lock system, the BCM will lock the vehicle doors if the following
inputs are  true:
|     •  | Ignition 1 input is active. | 
 
|     •  | All door jamb switch inputs are inactive. | 
 
|     •  | Cargo door or lift gate/lift glass ajar inputs are inactive. | 
 
|     •  | Transmission is shifted out of park | 
 
This automatic door lock function will only occur once per ignition
 cycle unless, a door jamb switch input changes state to active and back to
inactive.  Then the BCM will lock all doors again.
Once the automatic door lock feature has locked the doors, the BCM will
 then unlock all the doors when the transmission is shifted into park.