how to fix parking brake not releasing in BMW 3 Series G20/G21 (2019-2024)

Solution

1. Preparation

• Park the vehicle on a level surface and turn off the engine.
• Ensure the vehicle is in 'Park' mode (for automatic transmissions) or in gear (for manual transmissions).
• Disconnect the negative battery terminal to prevent accidental activation of electrical components.

2. Inspect and Test the Electronic Parking Brake

• Reconnect the battery and turn on the ignition (do not start the engine).
• Use an OBD-II scanner to access the electronic parking brake module.
• Check for any fault codes related to the parking brake and clear them.
• Attempt to engage and disengage the parking brake using the switch to test functionality.

3. Check the Brake Fluid Level

• Open the hood and locate the brake fluid reservoir.
• Inspect the fluid level; if low, top up with the appropriate brake fluid (DOT 4).
• After filling, repeat the testing of the parking brake functionality.

4. Inspect and Replace Parking Brake Cables (if necessary)

• If the cables are damaged or binding, lift the vehicle and remove the rear wheels for access.
• Detach the parking brake cables from the rear brake assemblies.
• Replace with new cables if they show signs of wear or damage. Ensure the new cables are routed correctly.

5. Reassemble and Test

• Reattach the wheels and lower the vehicle.
• Reconnect the negative battery terminal.
• Test the parking brake by engaging and disengaging it multiple times to ensure proper function.