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. The Key-less Entry Module detects and decodes the signals and issues signals to control the Door Locks, Trunk Release, Theft Deterrent System 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. The Automatic Door Lock feature is also incorporated in the Keyless Entry Module.


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 and simulate the Theft Deterrent arming sequence.

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. All Door Lock Motors run to lock all Doors.

With the Ignition Switch in OFF, the Keyless Entry Module will activate the Theft Deterrent disable output, pin C8, once. The Keyless Entry Module then activates the Door Jamb Output, pin C9, to simulate opening the Door. After all Doors lock, the Door Jamb Output will be deactivated to simulate the Door being closed. The Theft Deterrent System is now armed. If the Ignition Switch is ON, the Keyless Entry Module will lock all Doors, but the Theft Deterrent System will not be armed.


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 1112 seconds, all Doors will be unlocked. In both cases, the Theft Deterrent is disarmed and Illuminated Entry function is activated.

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 three operations.

1. The Keyless Entry Module will activate the Illuminated Entry output pin C7. 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, and the Courtesy Lights come on. See Interior Lights with Illuminated Entry. Testing and Inspection

2. The Keyless Entry Module will activate the Theft Deterrent disarm output at pin C8. The Theft Deterrent Module at pin H is pulled to ground and disarms the Theft Deterrent System.

3. 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 three unlock operations listed above. If the Ignition Switch is ON, only the LH Front Door will unlock. 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.

All Doors are unlocked automatically if the Vehicle Key is turned to unlock twice in the LH and RH Door Lock Cylinder. The Door Lock Cylinder Input (pin C5) 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.


TRUNK RELEASE
When the Transmitter Trunk Release Button is pressed with Ignition Switch OFF and the Key-less 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 Trunk Lid Release Relay (see schematic). The Trunk Lid Release Solenoid is energized and the Trunk Lid can be opened. Operation is similar when the Ignition is in RUN and the Gear Selector is in PARK. The Trunk 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. Operation of Courtesy Lights is similar to that when the Unlock Button on the Transmitter is pressed.


AUTOMATIC DOOR LOCKS (ADL)
The Automatic Door Lock feature will lock and unlock all Doors according to the states of the Transaxle Position Switch, Ignition Input, and Door Jamb Switches.

When the Doors are opened and then closed, the Door Jamb Switches CLOSE then OPEN (pin C9) and the Keyless Entry Module is triggered. When the Gear Selector is moved from the PARK position, the Park Input (pin C13) of the Keyless Entry Module senses the Gear Selector changing gear. If the Ignition Switch is ON (pin C14), the Keyless Entry Module then sends a voltage pulse to the Door Lock Relay and the Doors lock.

The Doors are unlocked automatically when the Gear Selector is moved to the PARK position. The Park Input (pin C13) of the Keyless Entry Module senses the Gear Selector changing gears. If the Ignition Switch is ON (pin C14), the Keyless Entry Module then sends a voltage pulse to the Door Lock Relay. The LH Door Unlock Output is also activated. All Doors unlock.