Nissan Altima 2002-2006 Key Programming Procedure
The following are the key programming procedures for Nissan Altima for the year 2002 to 2006.
ALL KEY FOBS MUST BE PRESENT WHEN PROGRAMMING NEW FOBS. (OLD REMOTES ARE ELIMINATED: BY OLDEST ONE FIRST AS NEW REMOTES ARE PROGRAMMED INTO THE VEHICLE)
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 10seconds. Your Hazard Lamps will flash if you performed this step successfully. NOTE: Withdraw key completely from ignition cylinder each time. If this procedure is performed too fast, the 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.
7. Test remote (s).
About Nissan Altima
For the 2002 model year, Nissan introduced the third-generation Altima (chassis model L31). It was the first mass-market vehicle to be constructed on Nissan’s innovative FF-L platform, which was exclusive to North America and lacked an equivalent model in Japan. The Asian Nissan Teana is close but not identical to the European Nissan Teana; all three model lines shared the same basis. The internal volume of the Altima increased dramatically for this generation, reaching 118.8 cubic feet (3.36 m3). The inside dimensions of the Altima even surpassed those of the higher-end 2000-03 Maxima, therefore the 2004 Maxima was repositioned further upscale into the full-size segment. The Altima’s fuel tank was also the largest in class at 20 US gal (76 L; 17 imp gal). In addition, the Altima’s rear suspension was modified to a multi-link design, and its brakes were upgraded to 4-wheel discs. The V6 engine was available for the first time in this model.
The 3.5 SE received a horsepower bump, from 240 hp (179 kW) to 245 hp (183 kW), however torque remained the same at 246 lbft (334 Nm).
Models with manual transmission from 2002 to 2004 were the lightest of the V6 (4DR) automobiles.
The sedan’s 2.5-liter 4-cylinder engine moved it from 0 to 60 mph (97 km/h) in 8.6 seconds.
The Nissan Altima was given a facelift in 2005, which included a new front grille, all-red taillights, a revamped interior, and an optional DVD-based navigation system. The V6 was now rated at 250 horsepower (186 kW), with torque at 249 lbft (338 Nm) and a 0–60 mph (97 km/h) pace of 6.2 seconds when equipped with the 5-speed automated transmission. The SE-R model was also introduced, with a 260 horsepower (194 kW) and 251 lbft (340 Nm) torque V6, a 6-speed manual transmission (automatic still offered), enhanced brakes, 18-inch wheels, a suspension firmer than the 3.5 SE’s, and a high-flow exhaust.  The SE-R was tested by Car and Driver and achieved 0–60 mph (97 km/h) in 6.1 seconds. MotorWeek episode #2432 put a SE-R with an automatic transmission through its paces, clocking a 0–60 mph time of 5.8 seconds.