2003 Lexus RX300

Programming Guide for 2003 Lexus RX300 Keyless Entry Remote Fob

Important Notice: The 2003 Lexus RX300 uses a manual procedure to program keyless entry remote fobs. The process must be followed precisely and within strict time limits. All remotes you wish to use must be programmed during the same session.

Available Programming Modes:

  • Add Mode – Adds a new remote without deleting existing ones (max 4).
  • Rewrite Mode – Erases all previous remotes and allows reprogramming.
  • Confirmation Mode – Displays the number of currently registered remotes.
  • Prohibition Mode – Erases all remotes and disables the wireless function (useful if a remote is lost or stolen).

Programming Instructions:

  • Step 1: Initial Setup Remove the key from the ignition. Make sure the driver’s door is open and unlocked, and all other doors are closed. Insert the key into the ignition once, then remove it.
  • Step 2: Enter Programming Mode Within 40 seconds: Press the power door lock switch to LOCK, then within 1 second press it to UNLOCK. Repeat this lock → unlock cycle five times. After the fifth cycle, close and then open the driver’s door.
  • Step 3: Select a Programming Mode Within 40 seconds: Repeat the same lock → unlock cycle five more times. Insert the key into the ignition. Turn the ignition from LOCK to ON, then back to LOCK, the number of times corresponding to your desired mode (see table below). Then remove the key from the ignition.
  • Step 4: Program the Remote(s) If Add, Rewrite, or Prohibition Mode was selected: Within 40 seconds, press and hold the LOCK and UNLOCK buttons on the remote simultaneously for at least 1.5 seconds. Then, within 3 seconds, press either the LOCK or UNLOCK button for at least 1 second.
  • Step 5: Confirmation If successful, the door locks will cycle once. If unsuccessful, they will cycle twice. If needed, repeat Step 4 within 40 seconds to try again or to add another remote.
  • Step 6: Finalize Programming Programming will end under any of these conditions: 40 seconds of inactivity. The driver’s door is closed. The key is inserted into the ignition. Four remotes have been successfully registered.

Additional Tips:

  • In Add Mode, previously stored remotes remain active unless the 4-remote limit is exceeded. In Rewrite Mode, all previous remotes are deleted—be sure to program all remotes again. Confirmation Mode helps check how many remotes are currently programmed. Prohibition Mode is best used when you’ve lost a remote and want to disable all existing ones.