* Low brake fluid: This is the most common reason. Check your brake fluid reservoir (usually a clear plastic container near the master cylinder under the hood). If it's low, you need to add brake fluid. Do not just add fluid, you need to find and fix the leak causing the low fluid. A low fluid level indicates a serious problem that needs immediate attention from a mechanic.
* Brake system malfunction: A problem with the brake system itself (worn brake pads, faulty sensor, etc.) will also illuminate the brake light. You will need to have this professionally diagnosed and repaired.
* Parking brake engaged: Make sure your parking brake is fully released.
* Faulty brake light switch: The switch is located near the brake pedal; it might be worn out or broken. This is a relatively inexpensive and straightforward part to replace, but you might need a mechanic to check it if you're not experienced with auto repairs.
* Burned-out brake light bulb: Check all brake light bulbs (including the high-mounted stop lamp, if your truck has one).
In short: There's no reset. The brake light is a warning indicator. Ignoring it is extremely dangerous. You *must* determine the cause of the illuminated light and fix the underlying problem. If you're not comfortable diagnosing brake issues yourself, take your truck to a qualified mechanic immediately.
