2005 Subaru Impreza Owner's Manual - Page 119
2005 Subaru Impreza Manual
Page 119 highlights
Keys and doors operates by operating each transmitter. Deleting old transmitter codes The control unit of the keyless entry system has four memory locations to store transmitter codes, giving it the ability to operate with up to four transmitters. When you lose a transmitter, the lost transmitter's code remains in the memory. For security reasons, lost transmitter codes should be deleted from the memory. To delete old transmitter codes, program four transmitter codes into the system. If you have only one current transmitter, program it four times. If you have two current transmitters, program each one twice. If you have three current transmitters, program two of them once and the third one twice. This process will leave only current transmitter codes in the system's memory. UG2042BA 3. Press and release any button on the transmitter that you wish to program into the system. The horn will sound twice to indicate that the transmitter has been programmed. Any additional transmitters can also be programmed at this time. Repeat steps 1 through 3 for an additional transmitter. To exit the programming mode: 1. After all of your transmitters are programmed, remove the key from the ignition switch. The horn will sound three times to indicate that the system has exited the programming mode. 2. Make sure that the keyless entry system properly 2-16 NOTE Make sure no one else is operating their keyless entry system within range of your vehicle when programming transmitters. If someone else were to operate their remote transmitter while you are programming your transmitters, it is possible that their transmitter code will be programmed into your system, allowing them unauthorized access to your vehicle.