Keyless Entry: Description and Operation
Keyless Entry System Description and Operation
Keyless Entry System Description and Operation - Active
The keyless entry system is a vehicle entry device. The keyless entry system is used in conjunction with the door locks to unlock the vehicle. Keyless entry will lock/unlock the vehicle doors or open the rear compartment lid when a corresponding button on the keyless entry transmitter is pressed. This is accomplished by the transmitter sending a radio frequency to the remote control door lock receiver antenna that has a direct link to the body control module (BCM). The BCM interprets the signal and activates the requested function or request the appropriate control module to activate the function via a serial data message. A low transmitter 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, such as gas stations that use pay-at-the-pump radio frequency transponders, may also cause interference that could lead to a malfunction. Keyless entry allows you to operate the following features:
* Door lock/unlock
* Remote start
* Charge port door release
* Illuminated entry lamps
* Panic alarm/Vehicle locator
* Remote vehicle start
Keyless Entry System Description and Operation - Passive
Passive keyless entry allows entry to a locked vehicle without pressing any buttons on the keyless entry transmitter. You must only have the transmitter with you. The passive entry system use low frequency antennas in several different areas on the vehicle to determine the location of the transmitter. When passively opening a locked door or the rear compartment, you must have a programmed transmitter with you in your pocket, purse, or briefcase.
When an exterior door handle button is pressed or the rear compartment touch pad is pressed, the low frequency antenna sends out a challenge to the keyless entry transmitter. Because of the low frequency, communication range is limited. The antenna will emit the challenged in a one meter range. The transmitter must be within this range to receive the challenge. The transmitter receives this challenge and emits it's response as an RF message, which is received by the remote control door lock receiver. If the response is correct, the door or rear compartment will unlock and open.
As a customer convenience feature, the keyless entry system will notify the driver if the transmitter has been left in the vehicle after exiting by chirping the vehicle horn three times. This may be turned off using vehicle personalization. Also, if the transmitter is left in the vehicle after the central door lock switch has been used to lock the vehicle, the driver door will remain unlock after exiting the vehicle. This is intended to prevent locking the transmitter in the vehicle and being unable to access it.
Keyless Entry System Description and Operation - Keyless Start
The keyless start portion of the keyless entry system allows vehicle starting, having only the transmitter as your key. The keyless start system use low frequency antennas in three different locations on the vehicle to determine the location of the transmitter. Multiple antenna are used to ensure complete coverage of the vehicle interior and rear compartment. When using the keyless start system, a programmed transmitter must be in the vehicle's interior, such as the driver's pocket, purse, or briefcase.
When the ignition mode switch is pressed, the low frequency antennas emit a challenge to the keyless entry transmitter. The transmitter receives this challenge and emits it's response as an RF message, which is received by the remote control door lock receiver. If the response is correct, vehicle starting will be allowed. If RF communication is interrupted, a "No Remote Detected" message will be displayed on the DIC. In these cases, the extended transmitter key blade can be placed in the transmitter slot located in the upper instrument panel storage compartment, under the rubber mat. The immobilizer antenna coil is located directly beneath the transmitter slot. Placing the extended key blade in the slot will create a low powered coupling between the transmitter and immobilizer antenna, allowing communications to occur and enabling vehicle starting.
The keyless entry system has the following components:
* Vehicle key with integrated keyless entry transmitter
* Driver and front passenger door antennas (part of the door handle assembly)
* Driver and front passenger door handle switches (part of the door handle assembly)
* Rear fascia antenna
* Front instrument panel console antenna
* Center console antenna
* Rear compartment antenna
* Body Control Module (BCM)
* Keyless entry control module
* Immobilizer antenna coil
* Remote control door lock receiver
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 start will operate at a distance of up to 20 m (65 ft) away. Vehicles with remote start will operate at a distance of up to 60 m (195 ft) away. The keyless entry transmitter is an integral part of the vehicle key.
Door Antenna
The keyless entry door antennas are used to transmit low frequency communications to the keyless entry transmitters.
The keyless entry door antennas are located in the left front and right front exterior door handle bracket. The antennas are serviced as part of the door handle assembly. The antennas are controlled by the keyless entry control module. When the exterior door handle button is pressed, the respective antenna will send out a challenge to the keyless entry transmitter, which begins the passive entry communications.
Rear Fascia Antenna
The rear fascia antenna is used to transmit low frequency communication to the keyless entry transmitters for entry to rear compartment.
The rear fascia antenna is located behind the rear fascia. The antenna is controlled by the keyless entry control module. When the rear compartment touch pad is pressed, the antenna sends out a challenge to the keyless entry transmitter, which begins the passive entry communications.
Front Console Passive (Instrument Panel) Antenna
This antenna is located in the lower instrument panel near the front of the center console.
The front console antenna is used for vehicle starting functions. When the ignition mode switch is pressed, the antenna is energized or "pinged". This emits a low frequency challenge signal that is received by the keyless entry transmitter. The transmitter will then reply to this challenge with a response and, if correct, vehicle starting will occur.
Center Console Antenna
This antenna is located in the rear of the center console.
The rear console antenna is used for vehicle starting functions. When the ignition mode switch is pressed, the antenna is energized or "pinged". This emits a low frequency challenge signal that is received by the keyless entry transmitter. The transmitter will then reply to this challenge with a response and, if correct, vehicle starting will occur.
Rear Compartment Antenna
This antenna is located in the center of the rear compartment metal floor pan, near the seatback.
The rear compartment antenna is used for vehicle starting functions. When the ignition mode switch is pressed, the antenna is energized or "pinged". This emits a low frequency challenge signal that is received by the keyless entry transmitter. The transmitter will then reply to this challenge with a response and, if correct, vehicle starting will occur.
Remote Control Door Lock Receiver
The remote control door lock receiver is located on the vehicle windshield, directly in front of the inside rearview mirror.
The remote control door lock receiver is control by and directly communicates with the body control module (BCM). When the transmitter receives a low frequency challenge from an antenna, it responds with an RF message. This RF message is received by the remote control door lock receiver and communicated to the BCM. If the RF message is a valid response to the low frequency challenge, vehicle access or starting will be allowed.
Immobilizer Antenna Coil Assembly
The keyless entry immobilizer coil assembly is located in the upper instrument panel, directly beneath the upper instrument panel storage compartment. If the transmitter battery is dead, weak, or the RF signal is being interrupted, the extended transmitter key blade can be placed in the transmitter slot located in the upper instrument panel storage compartment, under the rubber mat, to create a low powered coupling between the transmitter and immobilizer antenna, allowing communications to occur and enabling vehicle starting.
The immobilizer antenna coil is controlled by the BCM. The immobilizer control module is also active when learning vehicle keys.
Keyless Entry Control Module
The keyless entry control module is a multi-function module which performs the following keyless entry system functions:
* Activating vehicle antennas for passive keyless entry functions
* Activating vehicle antennas for keyless start functions
* Backup control for the ECM accessory wakeup and the run/crank relay
* If equipped, controls the electronic steering column lock
* Receiver of the exterior door handle switch inputs and door open switch (not the door ajar switch)
* Ignition mode switch monitoring
OnStar(R) Remote Link (if equipped)
A vehicle operator may have the ability to perform some of the keyless entry functions using applications on personal devices such as but not limited to smart phones. A condition may appear as if there is a malfunction in the vehicle. If it is suspected that this may be the case contact Technical Assistance if a condition cannot be determined through normal vehicle diagnostics.
Body Control Module (BCM)
The BCM is a multi-function module that performs the following functions:
* Receive and authenticate active transmitter and keyless start signals from the remote control door lock receiver
* Determines the functionality requested by the transmitter signal
* Performs the function requested by the transmitter signal
Unlock Driver Door Only - Active
Momentarily press the transmitter UNLOCK button to perform the following functions:
* Unlock only the driver door
* Illuminate the interior lamps for a determined length of time or until the ignition mode switch is pressed
* Flash the exterior lights, if enable through personalization
* Disarm the content theft deterrent system
* Deactivate the content theft deterrent system when in the alarm mode
Unlock All Doors - Second Operation - Active
Momentarily press the transmitter UNLOCK button a second time, within 5 seconds of the first press, to perform the following function:
Unlock the remaining doors and rear compartment
Unlock Driver Door Only - Passive
If enabled through personalization, approach the driver door with a valid keyless entry transmitter and press the door handle button to perform the following functions:
* Unlock and open only the driver door when door handle is operated
* Disarm the content theft deterrent system, if equipped
* Deactivate the content theft deterrent system when in the alarm mode
Unlock All Doors - Passive
Approach any non driver door (front or rear) or, if enabled through personalization, the driver door with a valid keyless entry transmitter and press the door handle button to perform the following functions:
* Unlock all vehicle doors and rear compartment
* Disarm the content theft deterrent system, if equipped
* Deactivate the content theft deterrent system when in the alarm mode
Lock All Doors - Active
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 content theft deterrent system
Lock All Doors - Passive
Exit the vehicle (with vehicle off) with the keyless entry transmitter to automatically perform the following functions, if equipped.
* Lock all vehicle doors and rear compartment after a delay
* Flash the exterior lights, if enabled through personalization
* Chirp horn, if enabled through personalization
* Arm the content theft deterrent system
When all doors are closed, they can also be locked from the exterior by pressing the door handle button while having a valid transmitter within range.
If more than one keyless entry transmitter is within a vehicle and the keyless entry system detects that one or more transmitters have been left in the vehicle after vehicle is locked, any transmitter left within the vehicle will be temporarily deactivated until:
* A button on the deactivated transmitter is pressed (will only activate the transmitter whose button is pressed)
* A passive unlock of vehicle occurs
* Change in power mode occurs
Rear Compartment Release - Passive
Approach the rear of the vehicle with a valid keyless entry transmitter. Press the trunk release touch pad. The trunk will open.
Vehicle Locator/Panic Alarm/Active
A single press of the panic button performs the following functions. Some functions may be dependent on personalization settings:
* Pulses the horn three times
* Flashes the exterior lamps three times
A press and hold of the panic button performs the following functions:
* A press and hold of the panic button performs the following functions:
* Pulses the horn and flashes the parking lamps for 30 second or until the following conditions occur:
- The panic button is pressed
- The ignition mode switch is pressed with a valid key in the vehicle
Remote Start
The remote start function allows an operator to pre-condition the vehicle interior prior to entering the vehicle. Remote start will allow the HVAC system and other vehicle systems to enable, providing a comfortable vehicle upon entry. Remote start functions have an operating range of up to 195 feet, depending on conditions. The remote start sequence begins by pressing and releasing the lock button and then pressing and holding the remote 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 a remote 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 HVAC and vehicle systems are allowed to operate for 10 minutes. The remote start time may be extended by an additional 10 minute by again pressing and releasing the lock button and then pressing and holding the remote start buttons on the transmitter. This feature is called a remote start continue and allows a maximum of 20 minutes of system operation. If the remote start continue is performed at 7 minutes into the initial 10 minute time-out, a total of 17 minutes of systems operation would occur. The remote start event may be suspended at any time by pressing only the remote start button on the transmitter or by entering the vehicle and turning ON the hazard lamps.
In between ignition cycles, only two remote start events may occur or be attempted. Once two events or attempts have been made, future remote start events will be suspended until the vehicle is operated using the ignition mode switch.
Enable/Disable Remote Start
Using the driver information center, remote start may be enabled or disabled as a part of vehicle personalization. Refer to the vehicle owners manual for more information.
Remote Start System Disabled
If any of the conditions listed below occur, a remote start event may be aborted or canceled:
* Vehicle is in valet mode
* Vehicle doors are ajar
* Rear compartment lid is ajar
* The hood is open
* The doors are not locked
* The hazard switch is ON
* Vehicle power mode is incorrect
* Vehicle speed is greater than 0
* Transmission is not in P
* Excessive engine coolant temperature
* Low oil pressure
* The malfunction indicator lamp (MIL) is commanded ON
* Engine crank time is greater than 30 seconds
* Excessive engine speed
* Accelerator pedal position too high
* Remote start timer equals 0
* Immobilizer system indicates a theft attempt
* Vehicle propulsion system fault conditions
* High voltage battery fault conditions
Keyless Entry Personalization
Vehicle lock/unlock functions and remote start settings may be personalized for the vehicle. For functional descriptions and programming instructions, refer to the vehicle owners manual.
Replace Battery in Remote Key Message
A REPLACE BATTERY IN REMOTE KEY message may be seen on the driver information center when the transmitter's battery voltage has been lower than 2.16 volts for three consecutive ignition cycles.