Keyless Entry System Description and Operation
The keyless entry system is a vehicle entry device. The keyless
entry system is used in conjunction with the body control module
(BCM) to remotely activate certain vehicle features. Keyless entry
will lock/unlock the doors/liftgate, operate the power liftgate (if
equipped), or release the liftglass when a corresponding button on
the keyless entry transmitter is pressed. This is accomplished by
the transmitter sending a radio frequency to the BCM. The BCM
interprets the signal and performs the requested function. A low
transmitter or vehicle battery or radio frequency interference from
aftermarket devices, such as 2-way radios, power inverters,
computers, etc., may cause a system malfunction. High radio
frequency traffic areas may also cause interference that could lead
to a malfunction. Keyless entry allows you to operate the following
components:
• |
Power liftgate, if equipped |
• |
Remote vehicle starting, if equipped |
• |
Illuminated entry lamps |
• |
Vehicle locator/Panic alarm |
• |
Comfort Open and Comfort Close, if equipped |
The keyless entry system has the following components:
• |
Keyless entry transmitters |
• |
Remote Function Receiver Module |
Keyless Entry Transmitters
The keyless entry transmitters are used to lock and unlock the
vehicle door while away from the immediate are of the vehicle.
Vehicles without remote vehicle start will operate at a distance of
up to 20 m (65 ft) away, except for Japanese and South
Korean vehicles, which are limited to 4 m (16 feet).
Vehicles with remote vehicle start will operate at a distance of up
to 60 m (195 ft) away. Up to 8 transmitters may be
programmed to a single vehicle.
Body Control Module (BCM)
The BCM is a multifunction module that operates the keyless
entry system. When an radio frequency message is received from a
keyless entry transmitter, the BCM interprets this signal and
performs the specific function, i.e. door lock, door unlock, or
vehicle locate.
Remote Function Receiver Module
The remote function receiver module is connected to the BCM with
a dedicated link. When a button is pressed on a keyless entry
transmitter, the remote function receiver module receives this
signal and sends the request to the BCM. The BCM interprets the
signal and performs the specific function, i.e. door lock, door
unlock, or vehicle locate.
Unlock Driver Door Only
Momentarily press the transmitter UNLOCK button in order to
perform the following functions:
• |
Unlock only the driver door. |
• |
Illuminate the interior lamps for a determined
length of time, or until the ignition is turned ON. |
• |
Flash the exterior lights, if enabled through
personalization. |
• |
Disarm the content theft deterrent (CTD) system,
if equipped. |
• |
Deactivate the CTD system when in the alarm
mode. |
Unlock All Doors - Second Operation
Momentarily press the transmitter UNLOCK button a second time,
within 5 seconds of the first press, to perform the following
functions:
• |
Unlock the remaining doors. |
• |
Unlock the liftgate, if equipped. |
Lock All Doors
Press the transmitter LOCK button to perform the following
functions:
• |
Lock all vehicle doors. |
• |
Immediately turn OFF the interior lamps. |
• |
Flash the exterior lights, if enabled through
personalization. |
• |
Chirp the horn, if enabled through
personalization. |
• |
Arm the CTD system, if equipped. |
Liftglass Release, if equipped
Press the transmitter liftglass release button to perform the
following function:
Open the liftglass.
Power Liftgate, if equipped
Press and hold the power liftgate button to perform the
following functions:
• |
Open or close the liftgate using the power
liftgate function. |
• |
Sound the interior power liftgate chime. |
Vehicle Locator/Panic Alarm
A single press of the panic button performs the following
functions. Some functions may be dependent on personalization
settings:
• |
Pulse the horn 3 times. |
• |
Flash the exterior lamps 3 times. |
A press and hold of the panic button performs the following
functions:
• |
Illuminate the interior lamps. |
• |
Pulse the horn and flash the exterior lamps for
30 seconds or until the following conditions occur: |
- |
The panic button is pressed. |
- |
The ignition switch is turned to the RUN position
with a valid key. |
Comfort Open and Comfort Closed, if equipped
Holding down the appropriate button on the transmitter will
perform the following functions:
• |
Open all vehicle windows |
• |
Close all vehicle windows |
Remote Vehicle Start, if equipped
The remote vehicle start function allows engine starting while
not in the vehicle. It also allows the vehicle HVAC system and
other vehicle systems to enable, providing a comfortable vehicle
upon entry. Remote Vehicle Start functions have an operating range
of up to 195 feet, depending on conditions. The remote vehicle
start sequence begins by pressing and releasing the lock button and
then pressing and holding the remote vehicle start buttons on the
keyless entry transmitter. The turn signal lamps will illuminate to
indicate the vehicle has received the remote start request. Each
time an remote vehicle start is performed, the vehicle doors are
locked, however they may then be unlocked/locked with the
transmitter or vehicle key at any time. Once activated, the engine
is allowed to run for 10 minutes. The remote vehicle start
time may be extended by an additional 10 minutes by again
pressing and releasing the lock button and then pressing and
holding the remote vehicle start buttons on the transmitter. This
feature is called a remote vehicle start continue and allows a
maximum of 20 minutes of engine running. If the remote vehicle
start continue is performed at 7 minutes into the initial
10 minute time-out, a total of 17 minutes of engine
running would occur. The remote vehicle start event may be
suspended at any time by pressing only the remote vehicle start
button on the transmitter or by entering the vehicle and turning ON
the hazard lamps.
In between ignition cycles, only 2 remote vehicle start
events may occur or be attempted. Once 2 events or attempts
have been made, future remote vehicle start events will be
suspended until the vehicle is started using the ignition.
Enable/Disable Remote Vehicle Start
Using the driver information center, remote vehicle start may be
enabled or disabled as a part of vehicle personalization. Refer to
the vehicle owners manual for more information.
Hood Ajar Switch
The hood switch provides status of the hood to the BCM for
remote vehicle start purposes. The switch is integrated into the
hood latch assembly. The hood ajar switch provides 2 separate
inputs to the BCM. These separate inputs allow the BCM to actively
monitor for a hood ajar switch fault.
Remote Vehicle Start Circuit Description
The BCM receives a signal from the keyless entry transmitter
indicating a remote vehicle start request. A message is then sent
to the BCM which determines if a crank request message will be sent
to the ECM to allow engine starting. To determine if conditions are
correct for an remote vehicle start event, the BCM will ensure the
following conditions are met:
• |
All vehicle doors are closed. |
• |
A valid hood ajar switch closed signal is
present. |
• |
The hazard switch is OFF. |
• |
The vehicle power mode is correct. |
• |
No content theft deterrent (CTD) alarm triggers
are present. |
• |
The vehicle is not in valet mode, if
equipped. |
When the BCM determines all conditions meet those required for
an remote vehicle start event, a message is sent via serial data to
the ECM. The ECM relies on the remote vehicle start message from
BCM to enable remote vehicle start when the crank request signal is
received. If the ECM does not receive a valid remote vehicle start
message, it will not attempt to start the engine. While the ECM is
in remote vehicle start mode it will suspend engine operation if
any of the following additional conditions occur:
• |
Vehicle speed is greater than 0. |
• |
Transmission is not in PARK. |
• |
Excessive engine coolant temperature |
• |
The malfunction indicator lamp (MIL) is commanded
ON. |
• |
Engine crank time is greater than
30 seconds. |
• |
Accelerator pedal position too high |
• |
Remote start timer equals 0. |
• |
Immobilizer system indicates tamper |
Keyless Entry Personalization
Vehicle lock/unlock functions and remote vehicle start remote
vehicle start settings may be personalized. For functional
descriptions and personalization instructions, refer to the vehicle
owners manual.
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