What is the reason for the ABS light being on?
3 Answers
The reasons for the ABS light being on are: 1. The ABS wire is broken or the plug is loose; 2. The electronic control device is of poor quality; 3. The fuse has blown for some reason. If the ABS light does not come on when the ignition switch is first turned on, the reason may be that the speed signal has not been transmitted to the ABS control unit. If the ABS sometimes works and sometimes doesn't, the reason may be a mechanical failure. If the ABS light is frequently on, it means the system has detected an ABS system error, and it is recommended to have it checked as soon as possible, as this is directly related to travel safety. When a fault occurs, it is necessary to first determine whether the vehicle's usual travel environment and the obstacles encountered by the car are related to the ABS fault, and then make corresponding repairs. Usually, the ABS light is on for a very short time, and if the system detects no problems after self-checking, it will turn off by itself. If you press the brake pedal quickly to the bottom while driving, the ABS light will also come on. Additionally, when the car is started, the ABS light may come on, but it will turn off when the brake is released.
The ABS light coming on is quite concerning to me because it involves braking safety. ABS stands for the Anti-lock Braking System, and when the light illuminates, it indicates a detected malfunction. Common causes include the wheel speed sensor being covered in mud or oil, leading to inaccurate signals; the sensor itself being damaged or worn out, resulting in erroneous data output; loose or short-circuited wiring connections causing signal interruptions; issues with the control unit module, such as software errors or hardware burnout; and blown fuses, which protect the circuit but cut off functionality. Driving, especially in rainy or snowy conditions, with a malfunctioning ABS can increase braking distance or the risk of tire lock-up. I've had a personal experience: after a long trip, the light came on, and upon inspection, it turned out the left front sensor connector was loose—pushing it back in turned the light off. It's advisable to regularly keep the sensors clean by wiping them with a soft cloth. If the light comes on, don’t delay; use an OBD diagnostic tool to scan for trouble codes or go directly to a repair shop—safety first.
The ABS light being illuminated indicates an abnormality in the anti-lock braking system. Technically, the ABS monitors the rotation speed of all four wheels via wheel speed sensors. If there's a discrepancy in the data from any wheel, the system will trigger an error and light up the warning lamp. Potential issues include: sensors being covered with oil and dirt affecting the magnetic ring, resulting in poor signal reception; internal components of the sensor burning out, leading to abnormal resistance values; the control module receiving incorrect signals and failing to analyze them properly, possibly due to water ingress or chip damage; short circuits or open circuits in the wiring, such as oxidized or loose connectors; or the hydraulic actuator valves being stuck or insufficient oil pressure. Modified vehicles or improperly installed electrical equipment can also easily interfere with the system and trigger the light. My recommendation is to start with the simplest checks: inspect if the sensors are dirty and try unplugging and reconnecting the connectors. If the light remains on persistently, do not ignore it—use a multimeter to measure the sensor resistance, which should normally be between 500-1500 ohms. It's best to visit a professional workshop for a quick diagnosis using specialized equipment, as this issue shouldn't be overlooked for daily driving safety. After all, the braking system is not something to take lightly.
