Four Possible reasons...
Low brake fluid - check the brake fluid level in the master cylinder
Emergency brake is on - check emergency brake
Low brake fluid pressure - such as a broken brake line or a bad wheel cylinder. Check the master cylinder to see if it is empty. If you add fluid and pump the pedal you will probably see brake fluid on the ground or on the inside of the tires.
Possibly a bad master cylinder. - The fluid will stay full but you will have no or little brake pressure.
Could be air in the system as well.
BE CAREFUL If you happen to add Power Steering fluid or Transmission Fluid to the master cylinder instead of brake fluid you will destroy the system. Make sure you use ONLY brake fluid and clean the master cylinder cap off with a clean rag first so no dirt gets into the braking system.
The transit brake warning light, on a Ford, can be reset by changing the brake pads. If the warning light is still on after changing the brake pads remove the fuse for 10 seconds.
You can reset the brake warning lights, on your VW Jetta, by backing up 20 feet and using the brakes. The automobile will sense the new pads and the warning light will go off.
The transit brake warning light, on a Ford, can be reset by changing the brake pads. If the warning light is still on after changing the brake pads remove the fuse for 10 seconds.
Check the brake fluid level, as on many vehicles the "emergency brake" (in the UK, Hand-brake) warning light also acts as a warning light for low brake-fluid.
That warning light means a light bulb is out. Check all of your brake lights (including the brake light on the rear dash!)
There is a sensor in the top of the brake cylinder where you put in the fluid. Replace it and the light will go away.
check your brake fluid it is probably low
The brake light is controlled by a relay switch. If the relay switch is bad the brake lights will stay on. The brake light switch simply plugs in and out. Unplug the brake light switch until you can replace it.
How do you reset the brake pad warning light for a 2005 c320 mercedes benz?
The brake warning light comes on in your dash if the emergency brake is on or the brake fluid level in the brake master cylinder in your engine compartment is LOW
...I have the exact same problem with my 1993 corolla.......Brake System warning light and discharge warning light
Once you correct the problem the light will go off. Can be low of brake fluid, parking brake might be partially on, defective Master Cylinder, etc. Do not ignore this light as this can cause your brakes to fail.