How to Open Bmw Fob Key

Opening a BMW key fob may mean opening the casing to replace the battery or using the hidden mechanical key to unlock the car.

Opening the Key Fob to Replace the Battery

For most newer BMW key fobs:

1. How to Open Bmw Fob Key: Find the small release button on the back or side of the fob.
2. Press and hold the button while pulling out the hidden mechanical key.
3. Look inside the opening for a small slot or notch.
4. Insert the tip of the mechanical key into the notch.
5. Gently twist the key to release the rear cover.
6. Remove the cover and take out the old battery.
7. Install a new battery of the same type, matching the original polarity.
8. Press the cover back into place until it clicks.
9. Reinsert the mechanical key.

Many BMW key fobs use a CR2032 battery, but some use a CR2450, CR2025, or another type. Check the number printed on the old battery before buying a replacement.

BMW Display Key

If your BMW key has a touchscreen display:

• It normally contains a rechargeable internal battery.
• It may charge through a USB connection or the vehicle’s wireless charging tray.
• The casing is not generally intended to be opened by the owner.
• If it will not charge or the screen remains blank, take it to a BMW dealer or qualified key repair specialist.

Forcing it open could damage the display, internal wiring, or water-resistant seals.

Older Diamond-Shaped BMW Keys

Some older BMW models use a diamond-shaped key:

• The battery is usually rechargeable and soldered to the circuit board.
• It normally charges while the key is in the ignition.
• The casing may not have a removable battery cover.
• Replacing the battery can require cutting the casing and soldering a new battery.

Professional repair is recommended because opening it incorrectly could damage the circuit board or immobilizer chip.

Unlocking the Car When the Fob Battery Is Dead

You can still unlock most BMW vehicles with the hidden mechanical key:

1. Press the release button on the key fob.
2. Pull out the mechanical key.
3. Check the driver’s door handle for a visible or concealed keyhole.
4. If concealed, carefully remove the small handle cover using the key and its access slot.
5. Insert the mechanical key into the lock.
6. Turn it to unlock the driver’s door.

The alarm may sound after the door is opened. In many models, hold the key fob against the marked area on the steering column and press the brake pedal and Start/Stop button. The vehicle should detect the key even if its battery is dead.