* Low Brake Fluid: This is the first and easiest thing to check. Low brake fluid indicates a leak somewhere in the system, which is a serious safety hazard. Top off the fluid (if safe to do so – see below) and carefully inspect brake lines and calipers for leaks. Do not drive the truck if you suspect a leak.
* Brake System Sensor Issues: Several sensors within the ABS system can trigger these warning lights. These include:
* Wheel Speed Sensors: These sensors monitor each wheel's speed. A faulty sensor will cause inaccurate readings, triggering the ABS and brake lights.
* ABS Module: The ABS module is the "brain" of the system. A faulty module can cause a wide range of problems, including the symptoms you describe.
* Brake Pressure Sensor: This sensor monitors brake fluid pressure. A malfunctioning sensor will trigger the warning lights.
* Faulty Brake Light Switch: While less likely to cause the ABS light to come on, a faulty brake light switch can prevent cruise control from working and illuminate the brake light.
* Wiring Issues: Damaged or corroded wiring within the braking system can interrupt signals and lead to these warning lights. This includes connections at the wheel speed sensors, ABS module, and other components.
Troubleshooting Steps (in order of safety and ease):
1. Check Brake Fluid Level: This is the most important first step. If low, *do not drive the vehicle* until you've determined the cause of the leak and fixed it.
2. Have the codes read: Use an OBD-II scanner to retrieve diagnostic trouble codes (DTCs). These codes will pinpoint the specific problem. Auto parts stores often offer free code reading services.
3. Inspect Brake Lines and Calipers: Look for leaks, especially around brake lines, calipers, and wheel cylinders.
4. Check Brake Light Switch: This is relatively easy to access and test. Consult your owner's manual or a repair manual for instructions.
5. Professional Diagnosis: If you can't identify the problem with the above steps or if you're uncomfortable working on your brakes, take your vehicle to a qualified mechanic. Brake system issues are serious and require professional attention.
Important Safety Note: Driving with illuminated ABS and brake lights is unsafe. The ABS system may not function correctly, and you may have reduced braking performance. Avoid driving the vehicle until the problem is diagnosed and repaired.
