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ABS System: What You Need to Know

img501137100 1462036778296 jpg ABS System | Cars.com photo by Evan Sears

The antilock braking system control module is a microprocessor that runs diagnostic checks of a vehicle’s ABS. It processes information from wheel-speed sensors and the hydraulic brake system to determine when to release braking pressure at a wheel that’s about to lock up and start skidding. Antilock systems prevent skids when braking, and stability control intervenes to prevent skids even when the brakes aren’t applied.
A dashboard ABS warning light is supposed to come on for a few seconds every time a vehicle is started, but if it comes on while you’re driving it signals that the control module has conked out, a wheel sensor has failed or another problem has developed.
On many vehicles, the brakes should still operate normally when the warning light is on, but the antilock function won’t work. On some vehicles, though, braking ability will be reduced if the antilock system malfunctions, and stability control and traction control (on vehicles with those features) might also be disabled.

How do I know if my ABS system is not working?
A warning light for the ABS is supposed to illuminate briefly every time you start your car. If the warning light stays on, that means the antilock system has been deactivated because of an electrical or mechanical malfunction. Your vehicle’s regular brakes should operate, but the antilock feature that prevents wheels from locking up during braking will not work. In addition, if your vehicle has stability control and traction control, those will be disabled too because they rely on the same wheel-speed sensors as the antilock system.

How often should I replace my ABS control module?
It’s the brains of the antilock braking system: a microprocessor that adjusts braking force to individual wheels to prevent skids based on signals from wheel-speed sensors. It is more likely that a wheel-speed sensor or other component exposed to the elements will fail before the control module, but as with other electronic components, it can happen. When it does, the antilock system will be disabled and an ABS warning light should illuminate.

Why do I have to replace my ABS control module?
Since the ABS control module manages the ABS, without it the ABS portion of your brakes won’t work. Before blaming the control module, a mechanic should diagnose whether the problem is a loose or corroded connection or a component at one of the wheels.

How much should I pay?
The cost of repairs can depend on where you are as much as it does on what you need fixed. To get an estimate for your repair, go to our estimator, plug in your car’s year, make and model information, add your ZIP code, and choose the repair you need. We’ll give you a range for what your repairs should cost in your area.

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