2021 Mercedes-Benz Metris Key Fob Programming Guide

Quick reference

Step-by-step on-board programming

The 2021 Mercedes-Benz Metris does not support DIY, on-board key fob programming. Mercedes-Benz vehicles, including the Metris, utilize advanced security systems that require specialized diagnostic equipment to program new key fobs. This process typically involves connecting to the vehicle's onboard computer (OBD-II port) and using manufacturer-specific software to synchronize the new key with the vehicle's immobilizer system. This is done to prevent unauthorized access and theft.

Therefore, a visit to a Mercedes-Benz dealership or a qualified automotive locksmith with the necessary diagnostic tools is essential for programming a new key fob.

Battery replacement

1. Locate the small release button or tab on the side or back of your key fob.
2. Press the button and simultaneously pull out the emergency key blade.
3. With the emergency key removed, you should see a slot or a small indentation. Use a small flathead screwdriver or a coin to gently pry open the key fob casing.
4. Carefully separate the two halves of the fob. The circuit board and battery will be visible.
5. Note the orientation of the CR2032 battery (positive side up). Gently pry out the old battery using a small non-metallic tool to avoid damaging the contacts.
6. Insert the new CR2032 battery with the positive (+) side facing up.
7. Align the two halves of the key fob casing and firmly press them together until they click securely into place.
8. Reinsert the emergency key blade.

Where to buy a replacement fob

• Mercedes-Benz Dealership: This is the most reliable option for obtaining a genuine key fob that is guaranteed to work with your Metris. They will also handle the cutting of the key blade and the programming.
  • Pros: Guaranteed compatibility, expert service, genuine parts.
  • Cons: Most expensive option. Expect to pay $300 - $500+ for the key fob, cutting, and programming.
• Automotive Locksmith: Many professional automotive locksmiths have the specialized equipment required to program Mercedes-Benz key fobs and cut the key blade.
  • Pros: Often more affordable than a dealership, convenient mobile services available.
  • Cons: Ensure the locksmith has experience with Mercedes-Benz keys and the correct diagnostic tools. Prices can vary. Expect to pay $250 - $450 for the fob, cutting, and programming.
• Amazon/Online Retailers: You may find "compatible" key fobs online, but these are often just the shell or an uncut key blade without the internal electronics, or they may be generic fobs that cannot be programmed to your specific vehicle.
  • Pros: Potentially lower initial cost for the physical fob.
  • Cons: Not recommended for the 2021 Metris. Without professional programming tools, an online purchase will not work. You will still need to pay for cutting and programming, and there's a high risk of purchasing an incompatible fob, leading to wasted money.

If on-board programming isn't supported

As established, the 2021 Mercedes-Benz Metris requires professional tools for key fob programming due to its advanced immobilizer and security systems. The key fob contains a transponder chip that communicates with the vehicle's immobilizer. This communication is encrypted and requires specific Mercedes-Benz diagnostic software to synchronize a new key. Attempting to use generic programming methods will not work and could potentially cause issues with your vehicle's security system.

Cost Expectations: As mentioned above, expect to pay anywhere from $250 to $500+ for a new key fob, including the cost of the fob itself, key blade cutting, and programming from a dealership or qualified independent automotive locksmith.

Find a mobile locksmith or shop on Repairius.