ABS and Anti-Lock Brake Repair

What the light means, and what it does not

A yellow or amber ABS light means the anti-skid system is switched off and the car has stored a code saying why. A red brake light is a different and more urgent message, usually low fluid or a problem with the brakes themselves, and that one means stop driving. If your traction control light came on at the same time, that is normal: both systems read the same sensors, so when one sensor quits, both features turn off.

Nine times out of ten it is a wheel sensor

Each wheel has a small sensor that counts how fast that wheel is turning. They live down by the brakes, in the dirt and the heat, so they fail for boring reasons: a corroded plug, a wire rubbed through where the suspension moves, metal grit stuck to the tip, or a cracked ring on the hub. The catch is that a bad sensor often reads perfectly fine sitting still and only drops out once you are moving. So we watch all four wheel readings live on a road test instead of testing one in the shop and calling it good.

When it is the pump unit instead

If the sensors and wiring check out, the problem is inside the ABS pump and valve unit, the box that does the actual pulsing. We test that by commanding it with a scan tool and watching whether it responds, rather than replacing an expensive part on a hunch. Worth knowing: old brake fluid that has taken on water is hard on that unit from the inside, which is one more reason we check fluid condition during a brake inspection.

ABS Repair: questions we get asked

More on brake repair

• Brake Pads & RotorsPad replacement, rotor machining or replacement
• Brake Fluid FlushSoft pedal, fluid testing, flush and bleed
• Brake Repair overviewPads, rotors, fluid, ABS

Related repairs

• Check Engine Light

Other services at the shop

• STAR Smog Check
• Auto A/C Repair
• Brake Repair
• Engine Diagnostics
• Radiator & Cooling
• Wheel Alignment

Where we serve

We serve drivers across the Coachella Valley:

• Palm Desert
• Cathedral City
• Rancho Mirage
• Palm Springs
• Indio
• Coachella
• La Quinta