why does my BMW 3 Series G20/G21 (2019-2024) traction control light keep coming on?

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface and set the parking brake.
• Disconnect the battery to prevent electrical shorts.

2. Inspect Wheel Speed Sensors

• Locate the wheel speed sensors on each wheel hub.
• Remove the sensor connector and inspect for dirt or corrosion.
• Clean the sensor surfaces with an appropriate cleaner if needed.
• Reconnect the sensors ensuring a tight fit.

3. Check ABS Module and Wiring

• Locate the ABS module under the hood.
• Inspect the wiring harness for any frays, corrosion, or loose connections.
• If any issues are found, repair or replace the affected wiring.

4. Test Traction Control Switch

• Locate the traction control switch on the dashboard.
• Remove the switch assembly and test its continuity with a multimeter.
• If defective, replace with a new switch.

5. Brake Fluid Level Check

• Open the hood and locate the brake fluid reservoir.
• Check the fluid level; if low, top off with the manufacturer-recommended brake fluid.
• Inspect for any leaks around brake lines or connections.

6. Verify Software Version

• Using the diagnostic tool, check the vehicle's software version.
• If an update is available, follow the manufacturer's instructions to apply the update.