Door Lock System Components
The power door lock system consists of the following components:
• | Rear door lock switch, utilities only |
• | Driver door unlock relay , uplevel vehicles |
• | Body Control Module (BCM) |
• | Reversible door lock actuators in each of the doors |
• | MIR/LOCK 3A fuse, switch supply voltage |
• | DR LOCK 20A fuse, relay supply voltage |
• | UNLOCK 15A fuse, unlock supply voltage |
• | LOCK 15A fuse, lock supply voltage |
• | UNLOCK JMPR, base vehicles |
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 , uplevel vehicles |
• | An automatic door lock function |
Driver and Passenger Door Lock Operation-Base Vehicles
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 DR LOCK fuse through
the battery voltage circuit. Voltage is then applied through the LOCK fuse 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.
Driver and Passenger Door Lock Operation-Uplevel Vehicles
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 DR LOCK fuse through
the battery voltage circuit. Voltage is then applied through the LOCK fuse to the
lock side of the door lock actuators. Since the other side of the passenger door
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 |
• | An automatic door lock function , if programmed |
Driver and Passenger Door Unlock Operation-Base Vehicles
When any of the door lock switches are placed in the unlock position, voltage
is applied to the door unlock signal circuit and the BCM. When the BCM senses the
voltage signal, it grounds the door unlock control circuit and the unlock relay winding.
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 DR LOCK fuse through the battery voltage circuit. Voltage is then applied through
the UNLOCK fuse to the unlock side of the door lock actuators. Since the other side
of the passengers door lock actuators are connected to the normally closed contacts
of the lock relay to ground, the doors unlock.
Passenger Door Unlock Operation-Uplevel Vehicles
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 and the
BCM. 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 DR LOCK fuse through the battery voltage circuit. Voltage is then applied
through the UNLOCK fuse 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.
The unlock function can also be accomplished by the BCM supplying voltage to
the door lock control circuit during any of the following:
• | A keyless entry unlock transmission |
• | An automatic door unlock function, if programmed |
Driver Door Unlock Operation-Uplevel Vehicles
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 or with an automatic door unlock function ,if programmed.
The driver door unlock relay differs slightly from the unlock relay in that the primary
side of the relay is connected to the DR LOCK 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 DR LOCK fuse through the battery voltage
circuit, the relay is energized. This causes the contacts to close and complete the
path from the DR LOCK 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 any of the following:
• | A keyless entry unlock transmission |
• | An automatic door unlock function, if programmed |
Delay Locking-Utility Vehicles
This feature allows the operator to lock all the doors from the rear lock switch.
The rear cargo doors have contact plates that complete the power door lock and unlock
fuse supply circuits ,among others, when the cargo doors are closed, and interrupt
these circuits when the cargo doors are open. When a lock function occurs and the
BCM senses an active state on the lift gate ajar switch signal circuit ,door open,
the driver and passengers doors will lock as described, and the BCM continues to
monitor the lift gate 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 cargo door.
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-Manual Transmission
The automatic door lock feature can be programmed to control the door lock
system. The automatic door lock feature is factory programmed to have no doors lock
or 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. |
• | Vehicle speed is greater than 24 km/h (15 mph) for 2 seconds. |
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 once the ignition key is removed from the ignition.
Programmable Automatic Door Locks-Automatic Transmission
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.