FAULTBASE
NEWSASKCars
© 2025 FAULTBASE
All rights reserved.
v2.0.0 • Production
ContactPrivacyImpressum
Home/Cars/BMW/3 Series/G20/G21 (2019-2024)/why does my BMW 3 Series G20/G21 (2019-2024) blind spot monitoring keep turning off?

why does my BMW 3 Series G20/G21 (2019-2024) blind spot monitoring keep turning off?

BMW 3 Series G20/G21 (2019-2024)

Severity: mediumDifficulty: medium1-2 hours
3 min read
524 words

Problem Statement

## Problem Statement The blind spot monitoring system in your BMW 3 Series G20/G21 (2019-2024) keeps turning off unexpectedly, potentially indicating a malfunction or sensor issue.

Repair Time
1-2 hours

Safety Warnings

  • ⚠Safety Warnings:**
  • ⚠Disconnect the battery before working on electrical components to prevent short circuits.

Symptoms

  • •Blind spot monitoring system indicator light is off
  • •Warning message displayed on the instrument cluster
  • •System intermittently activates and deactivates
  • •Reduced effectiveness of the blind spot alerts
  • •No audible or visual alerts when a vehicle is in the blind spot

Diagnostic Steps

  1. 1Scan the vehicle's onboard diagnostics using an OBD-II scanner to check for error codes related to the blind spot monitoring system.
  2. 2Inspect the exterior mirrors and rear sensors for any obstructions, such as dirt, snow, or ice.
  3. 3Verify the settings in the vehicle's infotainment system to ensure the blind spot monitoring feature is activated.
  4. 4Check the electrical connections and wiring for the blind spot sensors for any signs of damage or corrosion.
  5. 5Perform a visual inspection of the sensors for any physical damage or misalignment.
  6. 6Test the blind spot monitoring system's functionality in various driving conditions to check for consistent performance.

Solution

Solution

1. Preparation

  • Gather tools such as an OBD-II scanner, socket set, and cleaning supplies.
  • Ensure the vehicle is parked on a level surface with the engine off.
  • Disconnect the battery to avoid any electrical issues.

2. Clean the Sensors

  • Use a soft cloth and appropriate cleaning solution to gently clean the blind spot monitoring sensors located on the side mirrors and rear bumper.
  • Ensure no obstructions remain after cleaning.

3. Inspect and Secure Connections

  • Remove the side mirror covers and inspect the wiring harness connected to the blind spot sensors.
  • Tighten any loose connections and replace any damaged wiring.
  • Reassemble the side mirror covers securely.

4. Re-calibrate the System

  • Reconnect the vehicle's battery.
  • Start the engine and allow the vehicle to power up.
  • Follow the manufacturer’s instructions for recalibrating the blind spot monitoring system (refer to the owner’s manual or service manual).

5. Test the System

  • Drive the vehicle in a safe area to test the blind spot monitoring system.
  • Check that the system activates appropriately without turning off unexpectedly.

Verification

After completing the repair, verify that the issue has been resolved:

  • Test the affected component to ensure it functions correctly
  • Check for any error codes or warning lights
  • Monitor the vehicle for a few days to ensure the issue does not recur

Prevention Tips

To prevent this issue from occurring again:

  • •Follow the manufacturer's recommended maintenance schedule
  • •Address warning signs early before they develop into major issues
  • •Use quality parts and fluids recommended for your vehicle
  • •Keep detailed records of all repairs and maintenance

Tools & Equipment Required

  • OBD-II scanner
  • Socket set
  • Soft cloth
  • Cleaning solution

Parts Required

  • Replacement wiring harness (if damaged)
  • New sensors (if physically damaged)

Additional Information

Repair Time

1-2 hours

Difficulty

medium

Severity

medium

Tools

4 items

Parts

2 items

Related Faults

Discover similar issues

  1. how to fix BMW 3 Series G20/G21 (2019-2024) seatbelt warning not working

    ## Problem Statement The seatbelt warning system on a BMW 3 Series G20/G21 (2019-2024) is not functioning, leading to a lack of audio or visual alerts...

    Symptoms
    • •No warning chime when seatbelt is unfastened
    • •Seatbelt warning light not illuminated on the dashboard
    • +{count} more

  2. how to reset the check engine light in my BMW 3 Series G20/G21 (2019-2024)?

    ## Problem Statement The check engine light (CEL) is illuminated in a BMW 3 Series G20/G21 (2019-2024), and the user seeks instructions to reset it.

    Symptoms
    • •Check engine light illuminated on the dashboard
    • •Potentially reduced engine performance
    • +{count} more

  3. why does my BMW 3 Series G20/G21 (2019-2024) have a burning smell coming from under the hood?

    ## Problem Statement The BMW 3 Series G20/G21 (2019-2024) is experiencing a burning smell emanating from under the hood, which may indicate an issue w...

    Symptoms
    • •Burning smell noticeable from the engine bay
    • •Smoke or vapor visible in the area
    • +{count} more

  4. why does my BMW 3 Series G20/G21 (2019-2024) have a loud exhaust noise?

    ## Problem Statement The BMW 3 Series G20/G21 (2019-2024) is experiencing a loud exhaust noise, which may indicate an underlying issue with the exhaus...

    Symptoms
    • •Excessively loud exhaust sound, particularly during acceleration
    • •Possible rattling or buzzing noise while idling
    • +{count} more

  5. how to address the P0012 code in my BMW 3 Series G20/G21 (2019-2024)?

    P0012

    ## Problem Statement The P0012 code indicates a problem with the Variable Valve Timing (VVT) system, specifically that the exhaust camshaft timing is ...

    Symptoms
    • •Check engine light illuminated
    • •Rough idle or engine stalling
    • +{count} more

  6. my BMW 3 Series G20/G21 (2019-2024) has a hard start issue, what's causing it?

    ## Problem Statement The BMW 3 Series G20/G21 (2019-2024) is experiencing a hard start issue, where the engine is difficult to start or requires multi...

    Symptoms
    • •Engine cranks but does not start
    • •Extended cranking time before engine starts
    • +{count} more

Share this solution

Comments

Sign in to share your thoughts

Sign In

No comments yet

Be the first to share your thoughts

Back to Generation