Step 1: Gather Required Materials

• A new key fob compatible with the 2015 Toyota Tundra
• The existing key fob (if available)
• The vehicle’s Owner’s Manual (optional, but can be helpful)

Step 2: Enter Programming Mode

• Insert the existing key into the ignition and turn it to the "On" position, but do not start the engine.
• Wait for about 5 seconds, then turn the key to the "Off" position and remove it from the ignition.
• Within 40 seconds, close and open the driver's door twice, then insert and remove the key from the ignition.
• Within 40 seconds again, close and open the driver's door twice more, then insert the key into the ignition and leave it in the "On" position.
• Close and open the driver's door twice, which should put the vehicle in programming mode. The door locks should cycle, indicating that you have successfully entered programming mode.

Step 3: Program the New Key Fob

• Press any button on the new key fob within 40 seconds. The door locks should cycle to indicate that the new key fob has been programmed successfully.
• If you need to program additional key fobs, press any button on each additional key fob within 40 seconds of programming the previous one.

Step 4: Exit Programming Mode

• Turn the key to the "Off" position and remove it from the ignition. The door locks should cycle again to indicate that you have exited programming mode.
• Test the new key fob to ensure it is working properly by locking and unlocking the vehicle and checking other functions like the panic alarm and remote start (if applicable).

Tips and Warnings

• If the door locks do not cycle during any of these steps, restart the entire process from Step 1.
• If you are unable to program the new key fob yourself, consult a professional locksmith or your local Toyota dealership for assistance.