my BMW 3 Series G20/G21 (2019-2024) parking sensors keep giving false alerts, how to fix this?

Solution

1. Preparation

• Tools Required: OBD-II scanner, multimeter, cleaning supplies (soft cloth, mild detergent), basic socket set.
• Ensure the vehicle is parked on a level surface and the ignition is off.
• Disconnect the battery to avoid electrical shorts while working.

2. Clean the Parking Sensors

• Sub-steps:
  1. Locate the parking sensors on the vehicle's bumpers.
  2. Use a mild detergent and water solution with a soft cloth to gently clean the sensor lenses.
  3. Ensure that no dirt, mud, or ice obstructs the sensors.
• Safety Warning: Avoid using abrasive materials that may scratch the sensor lenses.

3. Inspect and Repair Wiring

• Sub-steps:
  1. Remove any necessary panels to access the wiring harness connected to the parking sensors.
  2. Visually inspect the wiring for frays, cuts, or corrosion.
  3. Repair any damaged wiring using appropriate electrical connectors and heat shrink tubing.
  4. Ensure all connections are secure and free from moisture.

4. Replace Faulty Sensors

• Sub-steps:
  1. Identify any sensors that failed the multimeter test.
  2. Remove the faulty sensor by unscrewing or unclipping it from its mounting point.
  3. Install the new sensor by reversing the removal process, ensuring it is secured properly.
  4. Reconnect the wiring harness to the new sensor.

5. Reconnect Battery and Test

• Sub-steps:
  1. Reconnect the vehicle battery.
  2. Start the vehicle and perform a test of the parking sensors by engaging reverse gear and checking for alerts.
  3. Ensure the sensors detect actual obstacles while ignoring false alerts.