how to fix my BMW 3 Series E90/E91 if the fuel gauge is stuck on empty?

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the vehicle's battery to ensure safety while working on electrical components.

2. Access the Fuel Sender Unit

• Tools Required: Socket set, flathead screwdriver, torque wrench.
• Remove the rear seat or trunk access cover to expose the fuel tank access panel.
• Unscrew and remove the access panel to reach the fuel sender unit.

3. Inspect and Test the Fuel Sender Unit

• Disconnect the electrical connector from the fuel sender unit.
• Use a multimeter to measure the resistance of the fuel level sensor. The resistance should vary as the float is moved.
• If the resistance is not within specifications (typically between 0 to 90 ohms), replace the fuel sender unit.

4. Replace the Fuel Sender Unit (if necessary)

• Remove any retaining screws or clips holding the fuel sender unit in place.
• Carefully lift the sender unit out of the fuel tank.
• Install the new fuel sender unit, ensuring it is seated properly and secured.
• Reconnect the electrical connector.

5. Reassemble and Test

• Replace the access panel and secure it with screws.
• Reconnect the battery.
• Start the vehicle and check the fuel gauge operation. Ensure it reflects the accurate fuel level.