Keyless Entry: Description and Operation

CIRCUIT OPERATION

The Remote Keyless Entry (RKE) Control System allows the driver to operate several vehicle features from outside the car using a hand held Radio transmitter. The Transmitter operates in the UHF band; it sends coded signals to the Keyless Entry Module via an antenna in the rear window. The Keyless Entry Module detects and decodes the signals and issues signals to control the Door Locks, Luggage Compartment Lid Release, and Illuminated Entry. These systems can also be operated in the usual manner; for instance, the Door Locks will respond to the Power Door Lock Switches.


LOCK

When the Lock Button is pressed on the Transmitter and the Keyless Entry Module receives a signal with a valid Vehicle Access Code (VAC), the lock function sequence is performed. The Keyless Entry Module will lock all Doors.

The Keyless Entry Module supplies battery voltage, pin C3, to the coil of the Lock Relay. The Lock Relay is energized, and battery voltage is supplied to the Door Lock Motors. Ground for the LH Door Lock Motor is provided at Keyless Entry Module terminal C16 through internal contacts. Ground for the RH Door Lock Motor is provided through the contacts of the Unlock Relay of the Door Lock Relay. Both Door Lock Motors run to lock all Doors.


UNLOCK

The Unlock function is separated into two operations depending on how the Unlock Button is pressed on the Transmitter. If the Unlock Button is pressed once, only the LH Front Door is unlocked. If the Unlock Button is pressed twice within 1-1/2 seconds, all Doors will be unlocked. In both cases, the Illuminated Entry function is activated (if there is low ambient light).

When the Unlock Button is pressed once on the Transmitter, and the Keyless Entry Module receives a signal with a valid VAC, the Unlock function sequence is performed. The Keyless Entry Module will simultaneously start two operations.

1. The Keyless Entry Module will activate the Illuminated Entry output pin C7 which simulates a door handle being lifted. The output signal is a 5 pulse signal, which is detected by the Body Computer Module (BCM) at pin 1C13. The BCM will then provide a ground for the Courtesy Lights at pin 1C1 (if there is low ambient light), and the Courtesy Lights come on, See Interior Lights repair.

2. The Keyless Entry Module will activate its LH Door Unlock Output at pin C16. Voltage will be supplied to the LH Door Lock Motor. The motor is grounded through the contacts of the Lock Relay in the Door Lock Relay. The LH Front Door Lock Motor runs to unlock just the driver's door.

If the Unlock Button on the Transmitter is pressed twice to unlock all Doors, the Keyless Entry Module will perform the same two unlock operations listed above. It will also activate the Door Unlock Output at pin C2. The Keyless Entry Module will then supply battery voltage to the coil of the Unlock Relay in the Door Lock Relay. The Unlock Relay is energized and closes its contacts. Battery voltage is supplied to the RH Door Lock Motor. The motor is grounded through the contacts of the Lock Relay in the Door Lock Relay. The motor runs to unlock the passenger's door.

If the Ignition Switch is ON, only the LH Front Door will unlock.

All Doors are unlocked automatically if the Vehicle Key is turned to unlock twice in the LH Door Lock Cylinder or RH Door Lock Cylinder. The Door Lock Cylinder Input (pin C8) is grounded through the Door Lock Cylinder Switch. This input will enable the Door Unlock Output (pin C2) as well as the LH Front Unlock Output (pin C16) to be activated. All Doors will unlock.


LUGGAGE COMPARTMENT LID RELEASE

When the Transmitter Luggage Compartment Lid Release Button is pressed with Ignition OFF and the Keyless Entry Module receives a signal with a valid VAC, the Keyless Entry Module will supply battery voltage at its terminal C1. This battery voltage is then applied to the Luggage Compartment Lid Release Solenoid. Operation is similar when the Ignition is in RUN and the Gear Selector is in PARK. The Lid will not release if the Ignition is in RUN and the Gear Selector is not in PARK.


ILLUMINATED ENTRY

When the Light Button on the Transmitter is pressed and the Keyless Entry Module receives a signal with a valid VAC, the Keyless Entry Module will activate the Illuminated Entry Output to the BCM which turns on the Courtesy Lights if there is low ambient light. Operation of Courtesy Lights is similar to that when the Unlock Button on the Transmitter is pressed.