GMC Sierra T1XX (2019-Present) brake warning light on, what does it mean?

Learn how to diagnose and fix the brake warning light issue in GMC Sierra T1XX (2019-Present). Step-by-step guide with symptoms, diagnostic steps, and repair instructions.

Solution

1. Preparation

• Tools Required: Socket set, brake fluid, OBD-II scanner, brake cleaner, jack and jack stands, torque wrench
• Ensure the vehicle is parked on a level surface and the engine is off.
• Disconnect the battery to prevent electrical issues during repairs.

2. Check and Top Off Brake Fluid

• Locate the brake fluid reservoir (usually near the driver's side of the engine compartment).
• Remove the cap and visually inspect the fluid level.
• If low, use the appropriate brake fluid type (DOT 3 or DOT 4, as specified in the owner's manual) to top it off.
• Replace the cap securely.

3. Inspect Brake Components

• Tools Required: Torque wrench, socket set
• Lift the vehicle using a jack and secure it with jack stands.
• Remove the wheels to access the brake components.
• Inspect brake pads for wear; replace if thickness is less than 3mm.
• Check rotors for scoring or warping; replace if necessary.
• Reassemble wheels and lower the vehicle.

4. Address Brake Line Leaks

• Inspect all brake lines and fittings for leaks or corrosion.
• If leaks are found, replace the damaged section of the line using a pipe cutter and brake line flaring tool.
• Bleed the brakes to remove air from the system after repairs.

5. Reset the Brake Warning Light

• Reconnect the battery.
• Use the OBD-II scanner to clear any stored trouble codes related to the brake system.
• Test the brake system by pressing the brake pedal to ensure it feels firm.