Keyless Entry: Description and Operation
Keyless Entry System Description and Operation
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 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 - 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
* 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.
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 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 keyless start functions
* Backup control for the ECM accessory wakeup and the run/crank relay
* Redundant power moding, in addition to the BCM
* Ignition mode switch monitoring
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
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
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
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 content theft deterrent system
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 switch is turned to the RUN position with a valid key
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.
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 (OFF to ACC or OFF to RUN).