Can a Toyota factory keyless entry 89741-AA020 be installed on a 2002 Toyota Camry LE that never had keyless entry?

SOURCE: Need factory code for keyless entry pad

To locate the original keypad code, open the passenger/rear door. Pull the on-body rubber weatherstrip out, around the rear side of the door closure. Fold the right/rear seatback down into the locked position to facilitate access to the right/rear seat belt anchor. Carefully pry the upper plastic panel that houses the height adjuster and seat belt anchor off the body taking care not to damage the panel. Now pry the lower panel outward just far enough to enable access to the Vehicle Security Module, where you'll see three electrical connectors plugged into it, coloured green, grey, and blue. On the module will be a series of digits on a label similar to 5L2T-15K602-EA. Beside those digits are five numbers. Those five numbers are the keyless entry keypad code.

SOURCE: program factory remote keyless entry for 2003 Hyundai XG350

This bulletin supersedes TSB# 02-90-001.
DESCRIPTION: The security system keyless adapter cable (SPX/Kent-Moore P/N 09900-21300) is a special service tool (SST) that is used for programming new keyless entry remote transmitters to the factory security systems. The keyless adapter is used in conjunction with the Hi-Scan Pro (with Hi-Scan SOL Pro Software Version 09-29-03
or newer) and Data Link Connector (DLC) Cable. SERVICE INFORMATION: The keyless adapter cable can be used on the following vehicles:

• 2001 - 2004 MY Elantra
• 2001 - 2004 MY Santa Fe
• 2002 - 2004 MY Sonata
• 2001 - 2004 MY XG300/350

• The 2003 - 2004 MY Tiburon does not need the Keyless Adapter Cable to add keyless entry remotes to the factory security system. Instead, the Hi-Scan Pro connects to the vehicle using only the DLC cable. See page BE-60 in the 2004 MY Tiburon Shop Manual for the latest instructions.
• The most current Keyless Adapter Cable Instructions are available in the following shop manuals:

1. Connect the keyless adapter cable to the Hi-Scan Pro DLC cable.
2. Plug the keyless adapter into the vehicle's 10-pin multi-purpose connector located behind the driver's side lower instrument panel (next to the DLC). NOTE Sample vehicle shown is the Santa Fe.
   
3. Turn the Hi-Scan Pro ON
   and press ENTER
   . NOTE "Release date 29. Sep. 2003" OR LATER
   must appear on this screen. To update your SOL card with the latest software go to www.hmaservice.com and refer to TSB 00-00-001.
   
4. Select option "HYUNDAI VEHICLE DIAGNOSIS"
   and press ENTER
   .
5. Select vehicle model and press ENTER
   .
6. Select option "TRANSMITTER CODE SAVING"
   and press ENTER
   .
7. Ensure that the key has been removed from the ignition cylinder before proceeding.
8. Follow the steps noted on the Hi-Scan Pro screen to program the remote(s). NOTE The factory security system can only be programmed to accept two remote transmitters and MUST be programmed for both remote transmitters at the same time.
   
9. Press ESC
   on the Hi-Scan Pro and verify that the remote(s) are functioning properly.
10. Turn the Hi-Scan Pro OFF
    and disconnect the adapter cable from the multi-purpose connector.

SOURCE: need to change the factory keyless entry code OR the module

Programming your own personal entry code
To program your own code:
5. Enter factory set code (keypad will illuminate when pressed).
6. Press 1/2 control within five seconds of step 1.
7. Enter your personal 5 digit code.
Enter each digit within five seconds
of previous one.
8. After the code is entered, the
locks will cycle, confirming that the
new code has been set.
Do not set a code that includes five of the same number or presents
them in sequential order. Thieves can easily figure out these types of
codes.

Keep in mind, if the battery is ever replaced or goes dead, the keycode will revert back to the factory setting.

SOURCE: Need to find the computer module with the factory

the code is usually found on stickers on the trunk hinges. if not remove the drivers door panel, the code is on the module that is in the door. use that code to access all functions including setting your own code.

SOURCE: cant find push button keyless entry code

They haven't put the code on the trunk lid for at least 10 years. On the 500/Montego, it's printed on a sticker on the Smart Junction box. This box is behind the fusebox (under the dash on the driver's side, above your left foot), so the sticker is facing the engine. You can use an inspection mirror to see the sticker, but I was able to get my digital camera behind there and take several pictures, and I was able to see the code.