How to Troubleshoot an Anti-Lock Brake System

Anti-lock brakes, or ABS, is a braking system enhancement that helps the driver to better control the vehicle during sudden and hard braking. The anti-lock brake system is most effective in inclimate weather, where there is a tendency for the vehicle's wheels to lock up. As you apply brake pedal pressure, the pedal will begin to rapidly pulse. This is the ABS system pumping the brakes for you to keep the wheels from locking up and your vehicle from skidding. If you're having trouble with the anti-lock brake system, you'll want to troubleshoot it to verify that the system is faulty.

Things You'll Need

  • Flashlight
  • Open the fuse box cover in your vehicle and locate the fuse for the anti-lock brake system.

  • Shine the flashlight directly over the top of the fuse for the ABS. Check to see if the fuse has popped. If it has, pull the fuse out and replace it with a new fuse.

  • Turn the ignition key to the "II" position. If the ABS light comes on and remains lit, then the anti-lock braking system has failed. Since the ABS unit is typically part of the wheel bearing assembly, any malfunctioning ABS unit needs to be replaced along with the bearing. Have this component serviced by a brake shop, as you need specialized knowledge and tools to press out the old wheel bearing to remove the ABS sensor.