Keyless Entry: Description and Operation

Remote Keyless Entry And Anti-Theft System Description

The remote keyless entry and anti-theft system can perform the following functions:
^ Remotely lock and unlock the vehicle doors by means of a hand-held, high-frequency transmitter.
^ Sense intrusion into the vehicle.
^ Activate a warning in the event of an intrusion.
^ Activate a warning when the PANIC button is pressed. (For HATCHBACK and STATION WAGON Model Only)
^ Help the driver find the vehicle in a parking area.
^ Automatically re-lock the doors if the door or the trunk/tailgate is not opened within 30 seconds after the vehicle has been unlocked by the remote keyless entry.
^ Communicate serial data to a scan tool to help diagnose system faults.


The remote keyless entry and anti-theft system consists of the following components:
^ Keyless entry and anti-theft control module/receiver.
^ Hand-held transmitter
^ Security indicator
^ Trunk/Tailgate open switch
^ Trunk/Tailgate tamper switch
^ Front door tamper switches
^ Door contact switches
^ Central door lock relay
^ Turn signal bulbs
^ Siren
^ Hood open switch

Remote Locking and Unlocking

The hand-held transmitter locks and unlocks the vehicle doors by sending radio waves to the control module/receiver in the vehicle. The effective range of the transmitter varies between 5 and 10 meters, (approximately 16 to 32 feet), depending on whether or not objects, such as other vehicles are blocking the path of the radio waves.

The transmitter has a LOCK button and an UNLOCK button which only function when the ignition is OFF. Pressing the UNLOCK button has the following effects:
^ The doors are unlocked.
^ The turn signal bulbs flash twice.
^ The control module is disarmed.

Pressing the LOCK button has the following effects:
^ The doors are locked.
^ The turn signal bulbs flash once.
^ The horn clips once.
^ The control module is armed.

The transmitter has a replaceable battery. The battery is designed to last at least two years before replacement is necessary.

Security Indicator

There is a security indicator ON the instrument panel. After the LOCK button of the transmitter is pressed, the module is placed in the armed mode, and the security indicator flashes. The security indicator turns ON for 0.1 second and OFF for 0.7 second. It then flashes at that frequency until the control module/receiver is disarmed.

Intrusion Sensing

The anti-theft function is armed if the transmitter sends the LOCK message to the control module/receiver when the ignition is OFF. When the hood, door, or trunk/tailgate is opened, the hood open, door contact, or trunk/tailgate open switch sends a "ground" signal to the control module/receiver. Unless the control module/receiver is disarmed, the siren will be activated when the "ground" signal is received from the trunk/tailgate open, hood open, or door contact switches.

The following actions disarm the anti-theft system:
^ An UNLOCK message is received from the transmitter.
^ Key operation is detected by the tamper switches. (The tamper switches are operated by the lock cylinders in the front doors and trunk/tailgate.)

The alarm will also be activated if the control module/receiver detects voltage from the ignition before either of the following conditions occur:
^ An UNLOCK message is received from the transmitter.
^ Key operation is indicated by the tamper switches.

Siren

The remote keyless entry system is armed when the LOCK message is received from the transmitter when the ignition is OFF. When the system is armed, it will activate the siren and flash the turn signals for 28 seconds if any of the following conditions occur:
^ A door is opened without using the key before an UNLOCK signal is received from the transmitter.
^ The rear deck lid is opened without using the key before an UNLOCK signal is received from the transmitter.
^ The hood is opened before an UNLOCK signal is received from the transmitter and before a door or the rear deck lid is unlocked.
^ The ignition switch input indicates battery voltage before either a key is used to unlock the vehicle or an UNLOCK signal is received from the transmitter.

The siren will not operate if any of the following conditions occur after the system has been armed:
^ The door is opened with the key.
^ The trunk/tailgate is opened with the key.
^ The UNLOCK or LOCK button on the remote transmitter is pressed.

Vehicle Locator

The remote keyless entry system assists the driver in locating the vehicle. When the vehicle is unlocked with the remote control, the turn signals flash twice to indicate the location of the vehicle. The duration of the flashes and the length of time between flashes is used to indicate certain vehicle conditions.

Autolocking (Safety Lock)

The remote keyless entry system features an autolocking feature. If the doors are unlocked with the remote transmitter when the control module/receiver is in the armed mode, the doors are automatically re-locked after 30 seconds unless any of the following events occur:
^ A door is opened.
^ The ignition is ON.
^ The trunk/tailgate is opened.
^ The hood is opened.

Panic (HATCHBACK and STATION WAGON Model Only)

The remote keyless entry system will activate the siren and flash the turn signals when the PANIC massage is received from the transmitter when the ignition is OFF.

A press of the PANIC button for 0.5 seconds performs the following functions:
^ The turn signal lamps flash for 0.25 seconds, with a 0.25 pause between flashes.
^ The siren is pulsed.

All of the above will continue for 28 seconds or until the PANIC button is pressed again.

Control Module/Receiver

The remote keyless entry control module/receiver is contained in the floor console. The module/receiver processes signals from the remote transmitter and various switches. It activates the alarm if an intrusion is detected. The control module/receiver also has a self-diagnostic function which will display trouble codes. In order to display trouble codes, a scan tool must be connected to the Data Link Connector (DLC).

The control module/receiver will not communicate with transmitters from other vehicles because there are over four billion possible electronic password combinations. It is highly unlikely that any transmitters will use the same password. The control module/receiver has an attached antenna to detect signals from the transmitter.

Fault or Alarm Indication

When the UNLOCK button on the remote transmitter is pressed, the control module/receiver will flash the turn signal lamps to indicate information about the remote keyless entry and anti-theft system.

Normal Condition: If there has not been an intrusion, and no fault has been detected, the control module/receiver will signal a normal condition when the UNLOCK button is pressed. The turn signal lamps will flash twice for 0.5 second, with a 0.5 second pause between flashes.

Alarm Indication: If there has been an intrusion since the last time the LOCK button was pressed, the control module/receiver will signal that there has been an intrusion when the UNLOCK button is pressed. The turn signal lamps will flash twice for 0.5 second, with a 1.5 second pause between flashes.

Alarm and fault information will be erased the next time the transmitter arms the control module/receiver by transmitting a LOCK message.