Herb,

Thanks for your response. It clarify things. I did a system flush with the Motive power bleeder two weeks ago hoping the sticking caliper problem and the ABS light would go away but it didn't.

Sometimes when I press the brake pedal I can hear a noise like metal pounding metal and at the same time my pedal goes down a little that makes me think that the sticking piston gets pushed out hard.

I've seen these symptoms since a year and a half when I bough this car, but just recently the ABS light started coming on in the mornings or after the car has been parked a few hours. I notice that if I hit the brakes hard a few feet after taking off the ABS light stays off, sometimes I hear the piston being pushed, but not all the times. Some other times the ABS light comes on despite of hitting the brakes hard; I learned that turning the engine off and then on at a stop light a few miles later, the light doesn't comeback.

My conclusion after all of that is that definitively have a bad caliper(s) and that is the reason of the ABS light as well. Any more thoughts?