I have a 2003 Silverado 1500 4.8L 4WD. For the last year or so my "Service Brake System" light will come on randomly. Sometimes when I hit bumps, sometimes when I'm driving down a smooth highway. When it comes on, it will chime for a good five minutes. Its very annoying. This just recently just started annoying me when I had a new radio installed. I cut the chime box off my old harness. My go-to mechanic said that it was more than likely a short somewhere and would cost me too much in labor for him to track it down. Also my ABS light stays on. It has been on solid for 3 years or so. The ABS scanner throws up the same codes Right or Left (don't remember which one) wheel speed sensor signal missing. The WSSs have been replaced twice on both sides since the wheel bearings have been replaced twice and if I remember right they sensors are built into the bearings. Has this happened to anyone else that might know what it could be? Likely things to check, etc... Any help is appreciated!