2019 Mercedes-Benz Sprinter Key Fob Programming Guide

As a locksmith and ASE-certified electrical technician, I get asked about Mercedes-Benz keys on a daily basis. The 2019 Mercedes-Benz Sprinter is a robust, highly capable commercial vehicle, but when it comes to the key fob and immobilizer system, it is built with some of the strictest security measures in the automotive industry.

If you have lost your key, need a spare, or are simply dealing with a dead battery, this guide will walk you through exactly what you need to know about your 2019 Sprinter's key fob.

Quick reference

Step-by-step on-board programming

If you are hoping to buy a cheap remote online and program it in your driveway using a sequence of button presses or ignition cycles, I have bad news: There is no DIY on-board programming procedure for the 2019 Mercedes-Benz Sprinter.

The 2019 Sprinter utilizes the Mercedes-Benz FBS4 (Drive Authorization System 4). This is a highly encrypted, rolling-code immobilizer system. It is designed specifically to prevent vehicle theft, which means adding a new key is virtually impossible without authorized, factory-level equipment.

To get a new key programmed:

1. Verification: The vehicle owner must present proof of ownership (title or registration) and a matching ID to an authorized dealer or a highly specialized locksmith with NASTF (National Automotive Service Task Force) credentials.
2. Ordering: A specialized, pre-coded "track" key is ordered directly from a Mercedes-Benz distribution center based on your Sprinter's exact VIN.
3. Programming: Once the key arrives, it must be synchronized to the vehicle's Engine Control Unit (ECU) and Electronic Ignition Switch (EIS) using a Mercedes STAR/XENTRY diagnostic scan tool.

Battery replacement

While you cannot program the remote yourself, you can absolutely change a dead battery. The 2019 Sprinter fob takes a standard CR2032 coin-cell battery.

1. Remove the emergency key: Look for the small release latch or button on the bottom/back of the key fob. Press it and pull the metal emergency blade out.
2. Open the casing: Insert the tip of the emergency blade (or a small flathead screwdriver) into the slot left vacant by the blade. Gently pry the back cover off.
3. Remove the old battery: Tap the fob against your hand or use your small screwdriver to pop out the old CR2032 battery.
4. Insert the new battery: Place the new CR2032 into the slot with the positive (+) side facing up.
5. Reassemble: Snap the back cover back onto the fob and slide the emergency key back into its slot until it clicks.

Where to buy a replacement fob

Because of the FBS4 security system, your options for purchasing a replacement key are extremely limited.

• The Dealership (Pros/Cons): The absolute safest and most reliable route. The dealer will order the exact OEM key (like part number A9079058703) pre-coded to your VIN. Pros: Guaranteed to work, official warranty. Cons: Very expensive, and you may have to tow the van to the dealership for the final synchronization. Expect to pay between $400 and $700 total.
• Specialized Automotive Locksmith (Pros/Cons): Only locksmiths who pay for authorized Mercedes NASTF access and XENTRY tools can help you. Pros: They can often come directly to your location, saving you a tow fee. Cons: Still expensive, and not every town has a locksmith equipped for 2019+ Mercedes vehicles.
• Amazon / eBay (Pros/Cons): Do not buy these. Used Mercedes keys are "locked" to the vehicle they were originally programmed to. Even "virginized" aftermarket keys often fail on the FBS4 platform. You will waste your money and no dealer or locksmith will agree to cut or program an internet-bought key for this vehicle.

If on-board programming isn't supported

As mentioned, on-board programming is completely unsupported. The FBS4 immobilizer transponder is integrated directly into the circuit board of the smart key.

If you are down to your last key, I strongly advise getting a spare made immediately. If you lose all keys to an FBS4 Sprinter, the costs skyrocket. You won't just be paying for a new key; in some "all keys lost" scenarios, depending on the exact module statuses, the EIS (Electronic Ignition Switch) may require complex bench work or replacement, which can easily push your bill over $1,500.

Always use the correct OEM part numbers, keep a fresh CR2032 battery in your fob, and don't trust online sellers claiming they have a "DIY fix" for a modern Mercedes-Benz.

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