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 a door 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 (RF) to the remote control door lock receiver (RCDLR). The RCDLR has an external antenna in the back glass that receives the RF signal. The RCDLR interprets the signal and activates the requested function via a serial data message. A low transmitter battery or RF interference from aftermarket devices, such as 2-way radios, power inverters, computers, etc., may cause a system malfunction. High RF traffic areas, such as gas stations that use pay-at-the-pump RF transponders, may also cause interference that could lead to a malfunction. Keyless entry allows you to operate the following features:

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. This passive system is also part of the vehicle starting system. It allows you to start and run the vehicle having only the transmitter as your key. The passive entry and starting system use low frequency antennas in 4 different areas on the vehicle to determine the location of the transmitter. When passively opening a locked door or the rear compartment lid, you must have a programmed transmitter with you in your pocket, purse, or briefcase. As a customer opens the door handle or presses rear compartment touch pad, the low frequency antenna sends out a challenge to the keyless entry transmitter. The transmitter must be in a one meter range of the door or rear compartment lid in order to receive the challenge. If the challenge is met, the transmitter will respond, allowing the door to be unlocked and opened. Passive entry allows you to operate the following features:

The keyless entry system has the following components:

The keyless entry transmitters are used to actively lock and unlock the vehicle doors, release the trunk, initiate a remote start event, and to initiate a panic alarm.

The transmitters can also be used passively to enter and start the vehicle. By pulling either of the front exterior door handles, a nearby programmed transmitter is challenged via the door antennas. The transmitter will respond by sending an RF signal to the RCDLR via its external antenna located in the back glass; the RCDLR will then interpret this communication and either allow entry into the vehicle or deny it.

Regardless of whether the transmitter is responding to an active function (button press on the fob) or a passive function (starting the vehicle), the transmitter ALWAYS responds via RF to the RCDLR’s external antenna.

The keyless entry door antennas are used to transmit low frequency communications to the keyless entry transmitters.

The keyless entry door antennas are molded into the vehicles LF and RF exterior door handles. The antennas are serviced as part of the door handle assembly. The antennas are controlled by the RCDLR. When the exterior door handle is pulled, the respective antenna sends out sends out a challenge to the keyless entry transmitter which begins the passive entry communications.

The rear compartment antenna is used to transmit low frequency communication to the keyless entry transmitters for entry to rear compartment.

The rear compartment antenna is located behind the rear fascia and is accessed from under the vehicle. The antenna is controlled by the RCDLR. 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.

The headliner and console passive antennas are used to transmit low frequency communication to the keyless entry transmitters to determine whether there are any inside the vehicle compartment.

The keyless entry headliner antenna is located under the vehicle’s headliner. The keyless entry console passive antenna is located under the trim below the cup holder. The antennas are controlled by the RCDLR and are driven simultaneously. When the vehicle’s start/stop button is pressed or when the doors are closed, these antennas send out a low frequency challenge to the keyless entry transmitter, which begins the passive communications.

The console active antenna is used to transmit a low frequency challenge to the transmitter in the event that the transmitter does not respond to the headliner/console passive antennas during a starting event. The active antenna is also used during transmitter programming events.

The keyless entry console active antenna is located in the center console. The console active antenna is controlled by the RCDLR. It has a small pocket next to it where the transmitter can be inserted if its battery is dead, weak, or the RF signal is being interrupted. If properly inserted in the pocket (buttons facing forward), the active antenna should always cause the transmitter to respond properly.

The RCDLR is a multi-function module which controls all the vehicles antennas for passive keyless entry functions. The RCDLR also acts as the receiver for active keyless entry and tire pressure monitoring (TPM) functions, as well as controlling all immobilizer functions.

The RCDLR’s RF antenna is located in the back glass, and there is a coax cable connecting the glass antenna to the module located in the trunk.

The external RF antenna is located in the back glass, just under the rear defrost grid. There is a coax antenna that connects the antenna in the back glass to the RCDLR. This antenna is responsible for receiving the RF communication from the TPM senders and the keyless entry transmitters (for both active and passive functions).

Momentarily press the transmitter UNLOCK button in order to perform the following functions:

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

If enabled through personalization, approach the driver door with a valid keyless entry transmitter and pull the door handle to perform the following functions:

If enabled through personalization, approach either front door with a valid keyless entry transmitter to perform the following functions:

Press the transmitter LOCK button to perform the following functions:

If enabled through personalization, exit the vehicle with the keyless entry transmitter to perform the following functions:

If more than one keyless entry transmitter is within a vehicle and the RCDLR detects that transmitter has been left in the vehicle after an exit, the transmitter left within the vehicle will be temporarily deactivated until the CTD system has been disarmed.

If the vehicle transaxle is in PARK or NEUTRAL and the ignition is in the OFF position, a single press of the transmitter rear compartment release button will open the rear compartment lid.

Approach the rear of the vehicle with a valid keyless entry transmitter. Press the rear compartment lid release touch pad. The rear compartment lid will open.

A keyless entry transmitter left inside the truck will allow the trunk to be reopened at any time. This feature will not allow a customer to lock the transmitter in the trunk.

A single press of the panic button performs the following functions. Some functions may be dependent on personalization settings:

A press and hold of the panic button performs the following functions:

The remote vehicle start (RVS) 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. RVS functions have an operating range of up to 195 feet, depending on conditions. The RVS sequence begins by pressing and releasing the lock button and then pressing and holding the RVS 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 RVS 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 RVS time may be extended by an additional 10 minute by again pressing and releasing the lock button and then pressing and holding the RVS buttons on the transmitter. This feature is called a RVS continue and allows a maximum of 20 minutes of engine running. If the RVS continue is performed at 7 minutes into the initial 10 minute time-out, a total of 17 minutes of engine running would occur. The RVS event may be suspended at any time by pressing only the RVS button on the transmitter or by entering the vehicle and turning ON the hazard lamps.

In between ignition cycles, only two RVS events may occur or be attempted. Once two events or attempts have been made, future RVS events will be suspended until the vehicle is started using the ignition.

Using the driver information center (DIC), RVS may be enabled or disabled as a part of vehicle personalization. Refer to the vehicle owners manual for more information.

The hood switch provides status of the hood to the BCM for RVS 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.

The RCDLR receives a signal from the keyless entry transmitter indicating a RVS request. A message is then sent to the BCM which determines if a crank request message will be sent to the ECM to activate RVS. The BCM looks at the following inputs to verify the system is ready for an RVS event:

When the BCM determines all conditions meet those required for an RVS event, a message is sent via serial data to the BCM. The ECM relies on the RVS message from BCM, to enable RVS when the crank request signal is received. If the ECM does not receive a valid RVS message, it will not ground the control circuit of the crank relay and start the engine. While the ECM is in RVS mode it will cut fuel to the engine if any of the following additional conditions occur:

Vehicle lock/unlock functions and remote vehicle start (RVS) settings may be personalized for the vehicle. For functional descriptions and programming instructions, refer to the vehicle owners manual.

A LOW FOB BATTERY message may be seen on the DIC when the fob’s battery voltage has been lower than 2.6 volts for three consecutive ignition cycles (OFF to ACC or OFF to RUN). The RCDLR monitors the voltage of each fob independently; however, if two fobs are present when starting the vehicle, the voltage will be monitored only on the fob that starts the vehicle. For example, if Fob 1 enters from the driver door and Fob 2 enters from the passenger door, the RCDLR will monitor only Fob 1. To determine the fob being monitored, check which driver ID is present when the vehicle is started. The driver ID will correspond with the fob being monitored.

Fob battery voltage may also be observed using the scan tool. The scan tool displays the actual battery signal voltage, as well as the low voltage signal. These parameters may be used to determine which fob has caused the LOW FOB BATTERY message to be displayed.