
Locate the car's battery, remove the negative terminal, and reconnect it after a few minutes to turn off the ABS warning light. The reasons for the ABS warning light being on are as follows: 1. The brake fluid level in the brake fluid reservoir is below the lower limit, and the brake fluid level indicator switch is activated; 2. Poor contact or damage to the parking brake switch or brake fluid level indicator switch; 3. Poor contact or short circuit in the ABS warning light's wiring; 4. Fault in the ABS system's ECU or its power circuit; 5. Intermittent fault in the wheel speed sensor or its wiring; 6. Failure of the brake pressure sensor or poor contact/short circuit in its wiring; 7. Air or other faults in the conventional braking system.

Last time my ABS light came on, I thought about trying to clear it manually. I disconnected the negative terminal of the battery, waited for over ten minutes, then reconnected it. After starting the car, the light went out, which felt good. But not long after driving, the light came on again, and I also noticed some abnormalities with the brakes. After checking online, I learned that the ABS system relies on sensors to detect wheel speed. If the sensors are dirty or the wiring is loose, the warning light stays on. Disconnecting the battery only temporarily resets the computer and doesn’t fix the root cause of the problem. Later, I went to a repair shop where they used a diagnostic scanner to read the fault code, which indicated a faulty left front wheel sensor. It was only after replacing it that the issue was completely resolved. An illuminated ABS light means the anti-lock braking function may be disabled, especially during emergency braking on slippery roads, making it easier for the tires to lock up, which is very dangerous. Manually clearing the light is just a temporary fix, and ignoring the problem could lead to an accident. It’s recommended not to tinker with it yourself and to seek professional inspection and repair as soon as possible—safety first.

The most reliable way to clear an ABS warning light is by using an OBD diagnostic scanner. Here's my go-to method when working on cars: Find a compatible scan tool and plug it into the OBD port under the steering wheel; start the vehicle and select the ABS module in the tool; read the fault code (e.g., C0021 indicates a sensor issue); after noting it down, press the clear button to turn off the light. However, if the sensor is contaminated or the wiring is broken without being fixed, the light will reappear quickly. The ABS system is safety-critical, and clearing the light is just one diagnostic step, not a solution. Ensure the wheel speed sensors are clean, connections are secure, and also check fuses and battery voltage. Simple issues can be handled yourself, but complex problems like module failures require professional repair. Tools are affordable now, or you can borrow one, but be careful not to accidentally trigger error codes during operation. Safe driving comes first—don't ignore a lit warning light.

When the ABS light comes on, don't just think about manually clearing it and feeling relieved. The light indicates an anti-lock braking system malfunction. Ignoring it may cause wheel lock-up and skidding during braking, which is extremely dangerous. I've experienced this situation before, and fortunately, I got it repaired in time. Clearing the code with a scan tool is quick, but not fixing sensor or wiring issues is like planting a time bomb. It's recommended to slow down and drive cautiously when the light is on, and visit a repair shop as soon as possible to read the fault codes. ABS relies on wheel speed sensors to function - if they're dirty or damaged, they need cleaning or replacement. Manual clearing methods like disconnecting the battery may temporarily turn off the light, but the problem will recur. Safety comes first - repairing the system is the real solution. Don't risk driving with it unrepaired - prevention is better than cure.


