how to fix the fuel gauge issue in BMW 3 Series E90/E91 (2005-2012)?

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Relieve fuel system pressure by removing the fuel pump fuse and starting the engine until it stalls.

2. Access Fuel Sender Unit

• Tools Required: Socket set, ratchet, torque wrench
• Remove the rear seat or access panel to reach the fuel pump cover.
• Unscrew the cover and disconnect the fuel lines carefully to avoid spilling fuel.
• Unplug the electrical connector from the fuel sender.

3. Remove Fuel Sender Unit

• Unscrew the locking ring that secures the fuel sender unit within the fuel tank.
• Carefully lift the fuel sender unit out of the tank, taking care not to damage the fuel pump or float arm.

4. Inspect and Replace

• Inspect the float arm for any signs of damage or blockage; replace if necessary.
• If the fuel sender is faulty, replace it with a new unit.
• Ensure all electrical connections are clean and secure.

5. Reassemble Components

• Reinstall the fuel sender unit and secure it with the locking ring to manufacturer torque specifications.
• Reattach the fuel lines and electrical connector ensuring a snug fit.
• Replace the fuel pump cover and re-secure the rear seat or access panel.

6. Final Checks

• Reconnect the negative battery terminal.
• Replace the fuel pump fuse and turn the ignition to the ON position (do not start) to prime the fuel system.
• Check for leaks around the fuel sender area before starting the engine.