What does it mean when the ABS light on the dashboard is on?
2 Answers
When the ABS light is displayed on the car, it indicates a malfunction in the vehicle's Anti-lock Braking System. If the wheels lock up during emergency braking, the vehicle may lose control and skid, making it difficult for the driver to slow down or adjust the vehicle's trajectory, which poses significant safety risks. There are various states in which the ABS light may illuminate, with different causes and solutions for each state, as detailed below: State 1: ABS warning light remains constantly on (most common). Cause 1: The ABS wheel speed sensor's sensing part is covered by dirt, mud, or other contaminants, affecting the sensor's ability to detect the corresponding speed signal. This prevents the ABS computer from determining the vehicle speed and the wheel slip rate, thus failing to issue appropriate commands to regulate braking. Solution: Clean the dirt from the wheel speed sensor and adjust the gap between the sensor and the signal ring to restore normal function. Cause 2: Poor signal due to loose connections in the system wiring or poor contact in the ABS relay, leading to system failure. Solution: Check the wiring connections and reconnect any loose parts. State 2: ABS warning light intermittently illuminates but turns off during acceleration. Cause: When multiple vehicle electrical devices are in use, the battery voltage drops below 10.5V. As the engine speed increases and voltage rises, the ABS light turns off. This may also occur if the ABS system's power supply voltage is too low due to poor terminal contact or grounding. Solution: Check the battery's specific gravity; inspect the charging system; examine the power supply (e.g., voltage relay or poor power contact). State 3: ABS warning light remains on after engine start and only turns off when the engine is turned off (IGFF). Cause: Poor grounding contact in the ABS hydraulic valve body; poor contact in the ABS hydraulic valve body wiring connector; ABS computer malfunction. Solution: Loosen the grounding screw on the hydraulic valve body, then retighten it, cleaning the contact surface if necessary; check if the connector gap has widened; replace the ABS or ABS/ASR computer. State 4: ABS warning light illuminates during high-speed driving. Cause: During high-speed driving, the ABS computer detects a significant discrepancy between the rear and front wheel speed signals; incorrect tire or wheel rim specifications. Solution: Refer to the vehicle's tire and wheel rim specifications, as indicated on the sticker near the fuel tank cap. State 5: ABS warning light intermittently illuminates. Cause: Improper adjustment of the brake light switch; poor internal contact in the brake light. Solution: Start the engine, press the brake pedal, use a finger to push the brake switch linkage fully downward, then release the brake pedal to complete the self-setting position; replace the brake light switch if necessary.
I saw the ABS light come on, which is the anti-lock braking system warning, indicating there's a problem with the system. When driving, the brakes might fail during skidding. I've been driving for over 20 years and have experienced this before. Once on the highway, the ABS light kept flashing, so I quickly pulled over to check. It turned out the sensor was clogged with mud, and after a simple cleaning, the light went off. If left untreated, the wheels could lock up during rain or emergency braking, making the car prone to skidding, which is very dangerous. So, it's important to regularly clean the sensor area during maintenance. When the light comes on, it means the computer has detected a fault—it could be loose wiring, a faulty module, or insufficient oil pressure. It's best not to delay; take it to a trusted repair shop to plug in a diagnostic tool and check the codes. It won't take much time to fix, and safety comes first.
