Three problems related to brake sensor have been reported for the 2003 GMC Sierra 1500. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2003 GMC Sierra 1500 based on all problems reported for the 2003 Sierra 1500.
Lost approximately 80% of braking power in a 2003 GMC Sierra 1500 with 60,000 miles. Small leak developed in the metal brake lines. There was no sensor indication that fluid was low despite brake fluid being one quart low.
Had dealership replace driver side front wheel bearing because it was making a grinding noise. A couple months later the front brake pads and rotors were replaced. After the brakes were serviced, I started noticing that the brakes were pulsating, which was felt in the pedal, at low speeds. Took vehicle to the dealership and they said during the test drive that the abs system was activating unnecessarily. They then put it on the diagnostic machine for some reasons. I was told I needed to replace both wheel abs sensors. The dealership said that the abs has nothing to do with the brake pads and rotors. When the pads and rotors were replaced, again the vehicle was put on the diagnostic machine, but didn't pick up that the sensors were firing. I'm doubting it is coincidence that these things are happening at random. There has to be some kind of correlation between the wheel bearing being replaced, the pads and rotors being replaced, and now the sensors needing to be replaced. My vehicle is a 2003 GMC sierra and has 47000 miles on it. All this happened within the last 6 months and 1500 miles.
2003 GMC Sierra 1500 with 70k miles. Have had problems on different occasions with the anti-lock brakes at low speeds. Had to replace sensors on all 3 occasions. Also, brake line busted which resulted in a near crash into a home. After further investigation, all brake lines leading in the antilock brake component were severally rusted. All brake lines needed to be replaced at a very hefty price.