what to do if my Volkswagen Passat B8 (2015-2022) has a brake warning light on?

Solution

1. Preparation

• Gather all necessary tools and parts.
• Ensure the vehicle is parked on a flat surface and engage the parking brake.
• Disconnect the negative terminal of the battery to ensure safety.

2. Inspect and Top Off Brake Fluid

• Tools Required: Brake fluid, funnel, cloth
  • Locate the brake fluid reservoir.
  • Check the fluid level; if low, clean the area around the reservoir cap, remove the cap, and add the appropriate brake fluid (DOT 4 recommended).
  • Recheck the level and ensure it is within the proper range before replacing the cap.

3. Inspect Brake Pads and Rotors

• Tools Required: Jack, jack stands, lug wrench, torque wrench
  • Lift the vehicle using the jack and secure it with jack stands.
  • Remove the wheel using the lug wrench.
  • Inspect the brake pads for thickness; replace if they are worn down to 3mm or less.
  • Check the rotors for scoring or warping; replace if damaged.
  • Reinstall the wheel and torque the lug nuts to the manufacturer’s specifications.

4. Check Brake Lines and Master Cylinder

• Tools Required: Brake line wrench, fluid catch pan
  • Inspect all visible brake lines for signs of wear or leaks.
  • If leaks are found, replace the affected sections of the brake line.
  • Check the master cylinder for any signs of fluid leakage or damage. If faulty, remove and replace the master cylinder.

5. Reset the Brake Warning Light

• Tools Required: OBD-II scanner
  • After repairs are complete, connect the OBD-II scanner to the vehicle's diagnostic port.
  • Clear any stored fault codes related to the braking system.
  • Disconnect the scanner and reconnect the negative battery terminal.