For 1990-2009 cars

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 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 remote control door lock receiver (RCDLR). The RCDLR interprets the signal and activates the requested function via a serial data message to the body control module (BCM). A low transmitter or vehicle battery or radio frequency (RF) interference from aftermarket devices, such as 2-way radios, power inverters, computers, etc., may cause a system malfunction. High RF traffic areas may also cause interference that could lead to a malfunction. Keyless entry allows you to operate the following components:

• | The door and liftgate locks

• | The power liftgate (if equipped)

• | The liftglass

• | Remote vehicle starting (if equipped)

• | The illuminated entry lamps

The keyless entry system has the following components:

• | The keyless entry transmitters

• | The keyless entry antenna (located in the vehicle glass)

• | The BCM

• | The RCDLR

### Keyless Entry Transmitters

The keyless entry transmitter are used to lock and unlock the vehicle door and rear compartment, operate the power liftgate (if equipped), as well as open the liftglass, from a distance of up to 60 feet (18 m) away. Up to 8 transmitters may be programmed to a single vehicle.

### Keyless Entry Antenna

The keyless entry antenna is used to receive radio frequency (RF) communications sent by the keyless entry transmitters. The keyless entry antenna also receives RF signals from the tire pressure monitoring (TPM) sensors located at each wheel.

The keyless entry antenna is an integral part of the vehicle windshield or rear glass, depending on application. A coax antenna lead connects the antenna to the remote control door lock receiver (RCDLR). When a transmitter button is present, the RF signal sent by the transmitter is received by the antenna and the communications are inputted to the RCDLR.

### Remote Control Door Lock Receiver (RCDLR)

The remote control door lock receiver (RCDLR) is a multifunction module that operates both the keyless entry system as well as the TPM system. When an RF message is received from a keyless entry transmitter, the RCDLR interprets this signal and will request via serial data that the body control module (BCM) perform the specific function, i.e. door lock, door unlock, or power liftgate open.

### 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 the driver information center (DIC).

• | 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.

### Lock All Doors - Active

Press the transmitter LOCK button to perform the following functions:

• | Lock all vehicle doors. Immediately turn off the interior lamps.

• | Lock the liftgate.

• | Flash the exterior lights, if enabled through the driver information center (DIC).

• | Chirp the horn if the LOCK button is pressed again within 5 seconds, if enabled through the DIC.

• | Arm the Content Theft Deterrent (CTD) System, if equipped.

### Liftglass Release

A single press of the transmitter liftglass release button will open the liftglass.

### Power Liftgate

Press and hold the power liftgate button to perform the following functions:

• | Open or close the liftgate using the power liftgate function.

• | Flash the vehicle tail lamps.

• | Sound the interior power liftgate chime.

### Panic Alarm/Vehicle Locator

Momentarily press the panic alarm/vehicle locator to perform the following functions:

• | Flash the turn signal lamps three times.

• | Honk the horn three times.

Press and hold the panic alarm/vehicle locator button for longer than 2 seconds to perform the following functions:

• | Flash the turn signal lamps for 30 seconds.

• | Honk the horn for 30 seconds.

### Remote Vehicle Start (RVS)

The remote vehicle starting feature allows engine starting from outside of the vehicle from a distance of up to 195 feet (60 m). It also activates the vehicles automatic climate control system, if equipped. If moderate or warmer outside temperatures exist, the climate control system will default to automatic temperature control and fan speed to regulate and maintain a moderate inside temperature. When the outside temperature is cold, the climate control system will start up the rear window defogger and default to the front windshield defrost mode with the heat on and the fan blower set to high. If the vehicle has heated seats, they will also turn on. Cooled seats, if equipped, are not activated during a remote start. Normal operation of the climate control system will return after the key is turned to RUN.

To operate the function, first press and release the lock button on the keyless entry transmitter, then immediately press and hold the remote vehicle start (RVS) button for 4 seconds. The vehicle park lamps will be illuminated to indicate that the engine is running. The RVS function is allowed to start the vehicle 2 times for 10-minute intervals. If the vehicle is left running it will automatically shut off after 10 minutes unless a time extension has been done. If the remote control door lock receiver (RCDLR) receives a second request for an RVS event while already operating in RVS, the first timer will expire and the second timer will start. For example, if 7 minutes after the initial RVS request, the RVS event is extended, the total time for the RVS event would be 17 minutes. To extend an RVS event, first press and release the transmitter lock button, then press and hold the RVS button. When you enter the vehicle during a remote start and the engine is still running, insert the key into the ignition, and turn the key to RUN to drive the vehicle; this will transition the vehicle to normal operation.

RVS can be deactivated by pressing the RVS button on the keyless entry transmitter, pressing the hazard switch, or by turning On the ignition, then turning it OFF. There are also other safety and security measures that will deactivate RVS, these include depressing the accelerator pedal or opening the hood. RVS may not function when DTCs are set. In these instances, the park lights will flash once when the RVS signal is received by the RCDLR, but the vehicle will not start. If the vehicle is put into valet mode, if equipped, by pressing the valet switch, RVS will also be disabled.

While in RVS mode all modules that are normally powered when the ignition is ON are active. All on-board diagnostics (OBD) II functions are also active.

The RVS feature can be turned off through the driver information center (DIC). Other RVS features may also be turned on or off via the DIC.

### Enable/Disable RVS

To disable the remote vehicle start (RVS) function, perform the following steps:

1. Turn ON the ignition, with the engine OFF.
2. Access the Remote Start personalization features within the driver information center (DIC).
3. Enable or disable the Remote Start feature.

The current state of RVS can be viewed through the DIC display under the Remote Start the display will read either ON or OFF.

When valet mode is enabled by pressing the valet switch (if equipped), RVS operation will be disabled.

### Hood Ajar Switch

The hood switch provides status of the hood to the body control module for remote vehicle start (RVS) and content theft deterrent (CTD) functions. It is integrated into the hood latch assembly. The hood ajar switch provides 2 separate inputs to the body control module (BCM). These separate inputs allow the BCM to actively monitor for a hood ajar switch fault.

### Circuit Description (RVS)

The remote control door lock receiver (RCDLR) receives a signal from the keyless entry transmitter indicating a remote vehicle start (RVS) request. A message is then sent to the body control module (BCM) which determines if a crank request message will be sent to the engine control module (ECM) to allow engine starting. To determine if conditions are correct for an RVS event, the BCM will ensure the following conditions are met:

• | The vehicle is not in valet mode (if equipped).

• | All vehicle doors are closed.

• | The liftgate is not ajar.

• | A valid hood ajar switch closed signal is present.

• | The doors are locked.

• | The hazard switch is OFF.

• | The vehicle power mode is correct.

• | No content theft deterrent (CTD) alarm triggers are present.

When the BCM determines all conditions meet those required for an RVS event, a message is sent via serial data to the ECM. 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 attempt to start the engine. While the ECM is in RVS 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

• | 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.

• | Vehicle theft deterrent (VTD) indicates tamper.

### Keyless Entry Personalization

Vehicle lock/unlock functions and remote vehicle start (RVS) settings may be personalized for 2 separate drivers. For mode descriptions and programming instructions, refer to the vehicle owners manual.

### Rolling Code

The Keyless Entry System uses rolling code technology. Rolling code technology prevents anyone from recording the message sent from the transmitter and using the message in order to gain entry to the vehicle. The term "rolling code" refers to the way that the Keyless Entry System sends and receives the signals. The transmitter sends the signal in a different order each time. The transmitter and the remote control door lock receiver (RCDLR) are synchronized to the appropriate order. If a programmed transmitter sends a signal that is not in the order that the RCDLR expects, then the transmitter is out of synchronization. This occurs after 256 presses of any transmitter button when it is out of range of the vehicle.

### Automatic Synchronization

The keyless entry transmitters do not require a manual synchronization procedure. If needed, the transmitters automatically re-synchronize when any button on the transmitter is pressed within range of the vehicle. The transmitter will operate normally after the automatic synchronization.