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Service Brake System Light

Discussion in 'General Chevy & GM Tech Questions' started by zachh1020, Sep 3, 2012.

  1. zachh1020

    zachh1020 New Member

    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!
  2. Pikey

    Pikey Moderator Staff Member 1000 Posts

    I would say that it could be a wheel speed sensor again. Especially if it is happening when you hit bumps. Have you checked the rear wheel speed sensor? Tracking it down yourself could take you some time but it will save you big time money. All you would really need is a multimeter and the specs. I would start by checking the resistance at the WSS. I can see if I can find out what the resistance should read for you.
  3. Blazer454

    Blazer454 New Member

    If the code if for signal missing the only explanation is a wiring problem. If the sensor is bad it will have a different code like signal erratic or signal low. Check the harness that goes to the sensor, make sure its pluged in all the way. Did this start after the bearings were replaced?
  4. zachh1020

    zachh1020 New Member

    It started before I had the bearings replaced the first time. The problem didn't resolve when they were changed the first or second time. I haven't checked the rear sensors yet. The codes were for one of the front sensors. It was giving missing, low and erratic. It spit out like 26 codes. Just a lot of repeats of the same code. Could the control box be bad? I really hope not, because if I remember right, those are expensive and expensive to replace.
  5. pcrepairshop

    pcrepairshop New Member

    I agree with Blazer454, this is probably a wiring issue. Either check the wires end-to-end with a multimeter, or inspect the wires from each sensor to the main control box. Also, check the contacts where each sensor plugs in and the plug at the main control box for corrosion. Try spraying some good electrical contact cleaner on the contacts to see if that straightens things out. Also, check the sensors to make sure there is no mud or other debris stuck in the rotor notches under each sensor. Good luck!

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