2018 Tesla Model 3 Key Fob Programming Guide

Quick reference

Step-by-step on-board programming

Unlike most vehicles on the road, which require a trip to a locksmith or dealership for expensive scan tool programming, Tesla has made adding a new key fob a simple, do-it-yourself process that can be done right from the driver's seat. The entire procedure uses the car's main touchscreen and an existing, working key to authorize the new one.

This process works for adding a new key fob, a new key card, or even your smartphone as a key. You will need at least one functioning and already-programmed key card or key fob to authorize the addition of a new key.

Here are the steps:

1. Get inside and power on: Sit in the driver's seat of your Model 3 and ensure the vehicle is on.
2. Navigate to the Locks menu: On the large center touchscreen, tap the car icon to bring up the Controls menu, then select Locks from the list.
3. Begin the "Add Key" process: You will see a list of currently programmed keys. At the top of this list, tap the + icon to add a new key.
4. Scan the new fob: A prompt will appear on the screen instructing you to scan the new key on the center console. Place your new, un-programmed key fob on the RFID reader located just behind the two front cup holders.
5. Authenticate with an existing key: After the car recognizes the new fob, it will require authentication. The screen will prompt you to scan an existing, already-paired key to approve the new one. Remove the new fob and place one of your original, working key cards or fobs in the same spot.
6. Confirmation: Once the system authenticates your old key, the new key fob is instantly paired and authorized. A confirmation message will appear on the screen, and you will see the new key added to the list. You can tap the pencil icon next to it to give it a custom name (e.g., "John's Fob").

That's it. Your new key fob is now ready to use.

Battery replacement

The Model 3 key fob uses a single CR2025 battery. It's a simple replacement:

1. Place the key fob button-side down on a soft, clean surface.
2. Using a small, flat-bladed tool or a spudger, carefully pry the circular bottom cover off the fob.
3. The battery will be exposed. Gently lift it out, being careful not to damage the contacts.
4. Insert the new CR2025 battery with the positive (+) side facing up.
5. Align the tabs on the cover and press it firmly back into place until it snaps shut.

Where to buy a replacement fob

• Tesla Service Center: This is the most reliable place to get a genuine OEM key fob. It's also the most expensive option, potentially costing $175 or more. However, you are guaranteed compatibility and quality. Since programming is so easy, you're just paying for the part itself.
• Automotive Locksmith: A certified automotive locksmith can often source OEM fobs or high-quality aftermarket alternatives, sometimes for less than the dealer. They are an excellent resource, but for a Model 3, their main value is in supplying the part, not the programming.
• Amazon/Online Retailers: You can find many aftermarket fobs online for as little as $50-$100. The risk here is quality and compatibility. Some may fail to program or stop working prematurely. This is the cheapest route but best for those comfortable with the risk of the part not working.

If on-board programming isn't supported

Fortunately, for the 2018 Tesla Model 3, on-board programming is the standard and only method. There is no need for external tools.

This is because Tesla's security and immobilizer system is fundamentally different from traditional cars. In a typical vehicle, a transponder chip inside the key fob must be registered to the car's immobilizer module using a proprietary scan tool that communicates over the OBD-II port. This process prevents theft by ensuring only authorized keys can start the engine.

Tesla integrates this security directly into the car's main computer. The on-screen, self-service programming procedure securely registers the unique ID of the new fob with the vehicle's central command unit. By requiring an already-authorized key to approve the addition, the system maintains a high level of security without requiring any special tools or a trip to the dealer. This seamless integration is a major advantage of Tesla's software-centric approach.

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