See also:

Clearing the programmed information
Individual buttons cannot be cleared. However, to clear all programming, press and hold the two outside buttons and release when the indicator light begins to flash (approximately 20 seconds). ...

Overview
The Altima is a mid-size car currently being manufactured by the Japanese automaker Nissan, and is arguably a continuation of the "bloodline" that began with the Nissan Bluebird in 1957. ...

Troubleshooting guide
Verify the location of all Intelligent Keys that are programmed for the vehicle. If another Intelligent Key is in range or inside the vehicle, the vehicle system may respond differently than expect ...