2003 Mercury Grand Marquis

Programming Guide for 2003 Keyless Entry Remote Fob

Important Notice: This vehicle supports onboard programming for standard keyless entry remote fobs. The procedure requires only the vehicle's ignition key and must be completed within specific time limits. All remotes must be programmed during the same session; any remote not included will no longer function.

Programming Instructions:

  • Step 1: Sit in the vehicle with all doors closed and all remote fobs you plan to program readily available.
  • Step 2: Insert the key into the ignition but do not start the engine.
  • Step 3: Within three seconds, turn the key from the OFF position to the RUN position four times, ending with the key in the RUN position on the fourth turn. Perform this step quickly and smoothly.
  • Step 4: Watch for confirmation—the door locks will automatically lock and unlock, signaling that the vehicle has entered programming mode.
  • Step 5: Within 20 seconds, press any button on the first remote fob. The door locks will cycle again, confirming that the remote has been successfully programmed.
  • Step 6: If programming a second remote, press any button on that remote within 20 seconds of programming the first. The locks will cycle again to confirm successful registration.
  • Step 7: Repeat Step 6 for any additional remotes, ensuring that each is programmed within 20 seconds of the previous one.
  • Step 8: Once all remotes have been programmed, turn the ignition key to the OFF position to exit programming mode.
  • Step 9: Remove the key and test each remote to ensure that the lock and unlock functions are working correctly.
  • Step 10: If any remote does not function, repeat the entire procedure from Step 1, making sure to follow the timing requirements carefully.

Additional Considerations: All remotes must be programmed during a single session. Any remotes not included will be erased from the system’s memory. Precise timing is essential. Delays in turning the key or pressing remote buttons can cause the programming mode to cancel. Check battery condition in all remote fobs before starting. Weak batteries can interfere with successful programming.