2000 - 2004 Nissan 4 Button Sentra & Maxima Keyless Entry Remote Fob - Made in Japan - NHVWBU43, NHVBU427

1.   Close and lock all doors with the driver’s side power lock/unlock switch.
 
2.   Insert key into ignition and remove it from the ignition key cylinder at least six times within 10 seconds. Your Hazard
     Lamps will flash if you have performed this step successfully. NOTE: Withdraw key completely from ignition cylinder
      each time. If this procedure is performed too fast, system will not enter programming mode.

3.   Insert key into the ignition cylinder and turn to the ACC position.

4.   Within 5 seconds, push ANY button on the remote transmitter. Your Hazard Lamps should flash. NOTE: Do not press
     the button more than one time in the above step. If the button is pressed more than one time, the programming
     procedure will not be successful.

5.   If there are any remaining transmitters (including the old ones), unlock then lock all doors using the driver’s side
     power lock/unlock switch and within 5 seconds, push ANY button on the next remote. Your Hazard Lamps should
     flash. Repeat this step for each transmitter (including any existing transmitters).

6.   Turn the key to the OFF position, remove keys from the ignition, unlock doors using the driver’s side power lock/unlock switch and open the driver side door.