Emergency brake warning light

I have a 2003 Sequoia. The emergency brake warning light has been coming on intermittently for the past few months. I have taken it to the dealership 4 times to fix the problem. The first time, they said a switch had fallen into the wrong position, the second time they added brake fluid, and the third time they changed out the contacts on the emergency beake pedal. After each fix the problem recurred. On the fourth try they could not find anything wrong without taking the system apart, but said it might be the sensor inside of the brake fluid tank. So the part is now in and I have to go back to the dealership.

I am at my wit's end. Has anyone else had this problem or know of a solution? Thanks in advance.

My dads 03 sequoia has the same problem. First time the dealer said it was the brake fluid levels so they topped that off and it was gone for months. Now its come back and The fluid levels are ok. Sometimes it stays on and we can't do anything about it. But sometimes if i stop and press the foot brake it will go off, or if I stop put the e-brake then release it it will stop. Then otehr times it will just remain lit untill I turn off the engine and turn it back on. From fourms i read around, it could be the brake sensor as you said, or just a computer or firmware problem. Not really sure why and our local dealers are stumped about it. If anyone has any other solution, it would be greatly appreciated.

Take it to a diferent dealer, ones that are not hacks and actualy try to fix cars.