What Causes a Car ABS Sensor to Fail?

[VonBrynlee]

There are two main reasons for the failure of a car ABS sensor: the ABS sensor being covered and loose connections in the system wiring. ABS Sensor Being Covered: When the sensing part of the ABS speed sensor is covered by dirt, mud, or other contaminants, it affects the sensor's ability to detect the corresponding speed signal. As a result, the ABS control unit cannot determine the vehicle speed or calculate the wheel slip ratio, preventing it from issuing appropriate commands to adjust braking. Cleaning the contaminants from the speed sensor and adjusting the gap between the sensor and the signal ring can restore normal function. Loose Connections in System Wiring: Poor signal quality caused by loose connections in the system wiring or poor contact in the ABS relay can lead to system failure. The most common issue is a loose speed sensor connector, which causes the fault. In such cases, the ABS control unit's fault memory will also indicate poor speed sensor signal quality. Check the wiring connections and reconnect any loose parts.

[DeAdeline]

I've encountered numerous cases of ABS sensor failures, mostly caused by physical damage and environmental factors. The sensors are installed near the wheels and are prone to direct damage from road debris like flying stones. Accumulated dirt and dust in the wheel hub area can block the sensors, leading to signal interruption. In winter, road salt with strong corrosive properties accelerates sensor rusting and aging. Electrical circuit issues are also common, such as aged wiring, loose connections, or short circuits that disrupt wheel speed data transmission. Careless handling of wiring during repairs can also cause problems. ABS sensors interact with magnetic rings and wheel speed rings to detect velocity. When faulty, the ABS warning light activates, and the braking system may fail, causing dangerous wheel lock-up during braking. It's recommended to stop immediately for inspection or visit a professional repair shop when this occurs to avoid accidents on slippery roads.

[JacksonLee]

I've been driving for over a decade and experienced ABS issues several times, mainly due to environmental corrosion and vibration damage. Once after a long trip, I found the sensor clogged with mud and non-functional because dirt thrown up by the tires stuck to it, interrupting the signal. Driving on salt-treated roads in winter caused rapid rusting and component failure. Vehicle jolts and excessive vibrations also led to sensor loosening or wire fractures. Physical impacts are common too, like hitting roadside curbs or damage from collision accidents. When ABS sensors fail, braking becomes problematic - wheels lock up and skid during braking, creating dangerous situations. Timely repairs are crucial. That time I spent over a thousand replacing the sensor, but it was worth it for safety. Now I always rinse the wheel hubs during car washes to prevent clogging.

[SanAmy]

When I was a beginner, the ABS light came on and I didn't know why. Later, the mechanic said it could be due to dirt blocking the sensor near the wheels, such as accumulated dust; aging wiring causing poor contact and signal interruption; or damage from driving too fast over bumps. New drivers might not pay attention to these details, and even water from washing the car could affect it. After a fault occurs, the ABS system may fail, making emergency braking dangerous as the wheels could lock up. It's recommended to simply check around the wheels for any debris. If you can't handle it yourself, go to a repair shop quickly.