1. Low Brake Fluid: Check the brake fluid level in the master cylinder reservoir. If it's low, top it up with the correct type of brake fluid recommended in the owner's manual.
2. Faulty Brake Fluid Sensor: If the brake fluid sensor is faulty, it might send incorrect signals to the instrument panel, triggering the "Check Brake System" warning.
3. Damaged or Worn Brake Pads/Shoes: Inspect the brake pads or shoes on all four wheels. If they are excessively worn or damaged, replace them as soon as possible.
4. Faulty Brake Light Switch: A faulty brake light switch might prevent the brake lights from illuminating when you press the brake pedal. Check the brake light switch and replace it if necessary.
5. ABS System Issue: If your Avalanche is equipped with an anti-lock braking system (ABS), there could be an issue with one of the ABS components, such as a wheel speed sensor or the ABS control module.
6. Electrical Problems: Electrical issues, such as a short circuit or a problem with the wiring, can also trigger the "Check Brake System" message.
If you're not confident in diagnosing and fixing the problem yourself, it's best to take your Avalanche to a qualified mechanic or a Chevrolet dealership for proper diagnosis and repair.
