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. Use the keyless entry system in conjunction with the door locks to unlock a vehicle. the keyless entry will unlock/unlatch a door or rear compartment lid when a corresponding button on the key fob is pressed. This is accomplished by the key fob sending a radio frequency to the remote control door lock receiver (RCDLR). The signal is received by the RCDLR via an internal antenna located within the RCDLR. Japan export vehicles are equipped with an external antenna. The RCDLR interprets the signal and activates the requested function via a class 2 message over the serial data line. A low transmitter battery or RF interference from aftermarket devices such as 2-way radios, power inverter, computers, etc. may cause a system malfunction. High RF traffic areas, such as gas stations which 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 components:
- The door locks
- The rear compartment lid release
- The illuminated entry lamps

The keyless entry system has the following components:
- The transmitters (up to 4 total)
- The RCDLR
- External antenna (Japan export only)

KEYLESS ENTRY SYSTEM DESCRIPTION AND OPERATION - PASSIVE
The passive keyless entry allows you to enter a locked vehicle without pressing any button on the key fob transmitter. You must only have the fob 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 fob 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 key fob to the vehicle. When passively opening a locked door or a rear compartment lid, you must have a programed key fob with you in your pocket/purse/breifcase. As a customer presses the door handle or rear compartment open pad, the low frequency antenna sends out a challenge to the key fob. The key fob must be in a one meter range of the door or rear compartment lid that the customer is opening in order to receive the challenge. If the challenge from the low frequency antenna is met, the key fob will respond to the remote control door lock receiver (RCDLR) via a radio frequency signal allowing the door to be unlocked and opened. Starting the vehicle also works in the same manner. The key fob must be within the passenger compartment of the vehicle when the Start/ACC/OFF button is pressed. The low frequency antenna sends a challenge to the key fob and if the challenge is met, the fob will respond to the RCDLR. The RCDLR will then send out a fuel enable password to the engine control module (ECM). As long as all security requirements are met and the ECM receives the password over the serial data line, the engine will start and run. A low transmitter battery or RF interference from aftermarket devices such as 2-way radios, power inverter, computers, etc. may cause a system malfunction. High RF traffic areas, such as gas stations which use pay-at-the-pump RF transponders, may also cause interference that could lead to a malfunction.

The passive keyless entry has the following components:
- The transmitters (up to 4 total)
- The RCDLR
- The keyless entry antenna - left, located in the lower B-pillar area at door height
- The keyless entry antenna - right, located in the lower B-pillar area at door height
- The keyless entry antenna - rear, located in the rear compartment area near the rear compartment lid latch
- The keyless entry antenna - back up, located inside the passenger compartment inside the glove box area

STARTING THE VEHICLE/ACC MODE
To start a vehicle you must have a valid key fob present within the passenger compartment of the vehicle, the brake pedal depressed and the transmission in Park or Neutral. If there are no problems with key fob detection, the vehicle will be able to be started or put into accessory mode when the Start/ACC/OFF mode button is pressed. If a key fob is not detected or the radio frequencies are being interrupted, a message will display on the driver information center (DIC) stating NO FOB DETECTED. A NO FOB DETECTED message may be caused by a low transmitter battery or RF interference from aftermarket devices such as 2-way radios, power inverter, computers, etc. High RF traffic areas, such as gas stations which use pay-at-the-pump RF transponders, may also cause interference. A NO FOB DETECTED message caused by an aftermarket device or high RF traffic is considered normal and does not require the replacement of any components. Replacing components in these situations will typically not increase the performance of the system. Simply moving the fob to a different location inside the vehicle may allow key fob communication to continue. If moving the key fob within the vehicle does not correct the message, a pocket is located in the glove box for the key fob to slide into. The key fob must be inserted into the pocket bottom edge first with the buttons facing towards the passenger side of the vehicle. With the key fob inserted into the pocket correctly, a low frequency coupling will occur between the key fob and the antenna when the Start mode or ACC/OFF mode button is pressed. This procedure will put the vehicle in limp home mode and allow the vehicle to be operated.

VEHICLE ON ENGINE OFF MODE
This mode is used to have all modules powered up and communicating on the serial data line. In order to achieve this mode the customer must have a valid key fob within the passenger compartment of the vehicle, the brake pedal depressed, and the transmission in Park or Neutral. Once that criteria is met, the customer must press and hold for 5 seconds the ACC/OFF portion of the Start/ACC/OFF mode button. The vehicle will power up with the engine OFF. A low transmitter battery or RF interference from aftermarket devices such as two-way radios, power inverter, computers, etc. may cause a system malfunction. High RF traffic areas, such as gas stations which use pay-at-the-pump RF transponders, may also cause interference that could lead to a malfunction.

TURNING OFF THE VEHICLE
When a vehicle is in a normal run mode, the key fob should already be present within the passenger compartment. To switch the vehicle to OFF mode, press the ACC/OFF portion of the Start/ACC/OFF mode button and the vehicle will power OFF. While in normal run mode if the key fob is removed from the vehicle it will not stall; the vehicle will continue to run as normal. However, if the vehicle is attempted to be powered OFF with no key fob present, the driver information center (DIC) will display a message to the customer stating NO FOB, OFF or RUN? At this point the customer has a final opportunity to continue to run the vehicle. Once a running vehicle is powered OFF with out a key fob present, the vehicle will not be able to be restarted until a valid key fob is present. On a normal power OFF, if the customer is exiting the vehicle and the key fob is left in the passenger compartment, the horn will chirp three times alerting the customer the key fob has been left in the vehicle. This feature can be turned On/Off through DIC personalization. Refer to Vehicle Personalization in Personalization.

UNLOCK DRIVERS DOOR ONLY - ACTIVE
Momentarily press the key fob UNLOCK button in order to perform the following functions:
- Unlock only the driver door.
- Illuminate the interior lamps for approximately 40 seconds, or until the ignition is turned ON.
- Flash the exterior lights, if selected ON in personalization.
- Disarm the content theft deterrent (CTD) system, if equipped.
- Deactivate the CTD system when in the Alarm Mode.

UNLOCK ALL DOORS-SECOND OPERATION-ACTIVE
Momentarily press the key fob UNLOCK button a second time, within 4 seconds of the first press, to perform the following functions:
- Unlock the remaining doors.
- Illuminate the interior lamps for approximately 40 seconds, or until the ignition is turned ON.
- Flash the exterior lights, if selected ON in personalization.
- Chirp the horn, if selected ON in personalization.

UNLOCK DRIVERS DOOR ONLY - PASSIVE
Approach the drivers door with a valid key fob to perform the following functions:
- Unlock only the driver door when door handle pad is pressed.
- Disarm the content theft deterrent (CTD) system, if equipped.
- Deactivate the CTD system when in the Alarm Mode.

UNLOCK ALL DOORS - PASSIVE
Approach the passenger door with a valid key fob to perform the following functions:
- Unlock the passenger and drivers door when that passenger side door handle is pressed.
- Disarm the content theft deterrent (CTD) system, if equipped.
- Deactivate the CTD system when in the Alarm Mode.

LOCK ALL DOORS - ACTIVE
Press the key fob LOCK button to perform the following functions:
- Lock all vehicle doors. Immediately turn off the interior lamps.
- Flash the exterior lights, if selected ON in personalization.
- Chirp the horn, if selected ON in personalization.
- Arm the content theft deterrent (CTD) system.

LOCK ALL DOORS - PASSIVE
With passive locking enabled in the driver information center (DIC) personalization, exit the vehicle with the key fob to perform the following functions:
- Lock all vehicle doors.
- Chirp horn, is selected ON in personalization.
- Arm the content theft deterrent (CTD) system.

REAR COMPARTMENT LID RELEASE - ACTIVE
If the vehicle transaxle is in PARK or NEUTRAL and the ignition is in the OFF position, a single press of the key fob rear compartment release button will open the rear compartment lid.

REAR COMPARTMENT LID RELEASE - PASSIVE
Approach the rear of the vehicle with a valid key fob, push the rear compartment open pad the rear compartment lid will open and raise.

KEYLESS ENTRY PERSONALIZATION
The exterior lamps and horn chirp may be personalized for two separate drivers as part of the remote activation verification feature. For mode descriptions and programming instructions, refer to Driver Personalization in Personalization.

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 resynchronize when any button on the transmitter is pressed within range of the vehicle. The transmitter will operate normally after the automatic synchronization.