Keyless Entry System Circuit Description. Buick GL7 (Export) 2000

For 1990-2009 cars

The keyless entry system is a supplementary vehicle entry device. Use the keyless entry system in conjunction with a door lock key. Radio frequencies or discharged batteries may disable the system. Therefore, always carry a door lock key.

Keyless entry allows you to operate the following components:

• | The door locks

• | The illuminated entry lamps

The keyless entry system has the following main components:

• | The transmitters

• | The remote control door lock receiver (RCDLR)

• | The body control module (BCM)

The RCDLR communicates with the BCM through the keyless entry serial data circuit. When you press a button on a transmitter, the transmitter sends a signal to the RCDLR. The RCDLR sends either a lock or unlock request to the BCM depending on which button is pressed on the transmitter. The BCM receives the message from the RCDLR and performs the appropriate function.

### Unlock Driver's Door Only

(BCM MODE 2 ONLY) Momentarily press the UNLOCK button in order to perform the following functions:

• | Unlock the driver's door only.

• | Illuminate the interior lamps for approximately 40 seconds or until the ignition is turned ON.

### Unlock All Doors (Second Operation)

(BCM MODE 2 ONLY) Momentarily press the UNLOCK button a second time within 5 seconds of the first press in order to perform the following functions:

• | Unlock the remaining doors.

• | Illuminate the interior lamps for approximately 40 seconds or until the ignition is turned ON.

(BCM MODE 1 ONLY) Momentarily press the UNLOCK button in order to perform the following functions:

• | Unlock all of the doors, including the driver's door.

• | Illuminate the interior lamps for approximately 40 seconds or until the ignition is turned ON.

### Lock All Doors

Press the LOCK button in order to perform the following functions:

• | Lock all of the doors

• | Immediately turn off the interior lamps

### 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 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 keyless entry system will not function.

### 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.