* Low Brake Fluid: This is the most common and easiest to check. Low brake fluid can trigger both warning lights. Check your brake fluid reservoir (usually a clear plastic container near the master cylinder) and top it off if necessary. However, if the fluid is low, don't just add fluid – find out *why* it's low first. A leak is a serious problem.
* ABS Sensor Issues: One or more of your Anti-lock Braking System (ABS) wheel speed sensors might be malfunctioning, dirty, or have a wiring problem. These sensors measure wheel speed for the ABS system. A faulty sensor can trigger the ABS and brake lights. The speedometer uses a different sensor, which is why it still works.
* ABS Module Problem: The ABS control module itself could be faulty. This is a more complex and expensive repair.
* Brake Light Switch: While less likely given the ABS light is also on, a faulty brake light switch could also contribute. This switch signals the brake lights and sometimes interacts with other systems.
* Wiring Issues: A short circuit or damaged wiring related to the ABS system can also cause both lights to illuminate.
What to do:
1. Check the Brake Fluid: This is the absolute first thing you should do. If low, find the leak!
2. Have it Diagnosed: The best course of action is to take your truck to a mechanic or auto parts store that can perform an OBD-II scan. This scan will read the trouble codes stored by the vehicle's computer, giving a much more precise indication of the problem.
3. Don't Drive It (If Brake Fluid is Low or You Suspect a Major Problem): Driving with a serious brake problem is extremely dangerous. If you suspect anything beyond low brake fluid, avoid driving until the issue is diagnosed and fixed.
Ignoring the warning lights could lead to brake failure. Get it checked out as soon as possible.
