These instructions apply to the Mercedes Sprinter Mk3 (W907/W910) 2018-Present.
For other models, please choose your vehicle here.
When your Sprinter’s fob won’t lock or unlock and its indicator lamp stays dark, the coin cell is flat. You can still get in and start the van, then swap the battery in a couple of minutes.
- Get in: press the small release button on the fob so the emergency key blade slides part-way out, then pull it fully out.
- Put the blade into the driver’s door lock cylinder and turn it anticlockwise to unlock (turn clockwise on a right-hand-drive van). The alarm may sound until the van recognises the key inside.
- Start it: sit in, place the fob into the key holder slot in the shift console (the marked position), then press the START/STOP button as normal. The van reads the fob at close range even with a flat battery.
- Replace the battery: with the fob out, press the release button and pull the emergency key blade out first.
- Press the release button fully and slide the cover forward off the fob.
- Pull out the battery tray and lift out the old CR2032 cell.
- Fit the new 3V CR2032 with the plus (+) side matching the marking in the tray.
- Slide the tray back in, refit the cover until it clicks, and push the emergency key blade back until it locks.
Troubleshooting
If the van is locked with your only key shut inside, don’t force it — call a workshop to open it safely.
Had a key lost or stolen? A workshop can bar (deactivate) that fob so it can no longer start the van, and re-key the locks if needed.
Keep the fob away from phones and loose metal, which can weaken its signal and shorten range even with a good battery.
FAQ
What battery does the Sprinter key fob take?
A single 3V CR2032 coin cell. Fit it with the plus (+) side facing the marking in the tray.
How do I start the van if the fob is dead?
Sit in, drop the fob into the key holder slot in the shift console (the marked position), then press the START/STOP button as usual. The van reads it at close range even with a flat battery.
How do I get in if the central locking is dead?
Press the release button on the fob, pull out the mechanical emergency key blade, and turn it in the driver’s door lock cylinder — anticlockwise to unlock (clockwise on a right-hand-drive van).
Why did the alarm sound when I used the emergency key?
That’s normal. Unlocking with the blade can trigger the alarm until the van recognises the key is inside; it stops once you switch on.
Independent guide — not affiliated with Mercedes. Always follow your official service manual and safety precautions. Read our full disclaimer.