GM Service Manual Online
For 1990-2009 cars only

Keyless Entry System Description

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 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. 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:

    • Door locks
    • Illuminated entry lamps

The keyless entry system has the following components:

    • Keyless entry transmitters
    • RCDLR

Keyless Entry Transmitters

The keyless entry transmitters are used to lock and unlock the vehicle door while away from the immediate area of the vehicle. The keyless entry system will operate at a distance of up to 30 feet (9 m) away.

Remote Control Door Lock Receiver (RCDLR)

The remote control door lock receiver (RCDLR) is a multifunction module that operates the keyless entry system. When an RF message is received from a keyless entry transmitter, the RCDLR interprets this signal and performs the specific request function.

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

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 function:

Unlock the remaining doors and the liftgate

Lock All Doors

Press the transmitter LOCK button to perform the following functions:

Lock all vehicle doors

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.

Resynchronization

Resynchronization may be necessary due to the security method used by the keyless entry system. The transmitter does not send the same signal twice to the receiver. The receiver will not respond to a signal it has been sent previously. This prevents the recording and playing back the signal from the transmitter.

To resynchronize a transmitter, stand close to the vehicle and simultaneously press and hold the LOCK and UNLOCK buttons on the transmitter for at least five seconds. The door locks will cycle to confirm resynchronization.