What does it mean when the ABS light appears on the dashboard?

[DiEliana]

There are various conditions when the ABS light is on, with different causes and solutions for each condition. The details are as follows: Condition 1: ABS warning light stays on (most common). Cause 1: The ABS wheel speed sensor's sensing part is covered by mud, sludge, or other contaminants, affecting its ability to detect the corresponding speed signal. This prevents the ABS control unit from determining the vehicle speed and 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: Loose connections in the system wiring or poor contact in the ABS relay can lead to signal issues and system failure. Solution: Check the wiring connections and reconnect any loose parts. Condition 2: ABS warning light intermittently turns on but turns off when accelerating. Cause: When multiple vehicle electrical devices are in use, the battery voltage drops below 10.5V. The ABS warning light turns off as the engine speed increases and voltage rises. The ABS system power supply voltage is too low, possibly due to poor terminal contact or grounding issues. Solution: Check the battery's specific gravity; inspect the charging system; examine the power supply (e.g., voltage relay or poor power contact). Condition 3: The ABS warning light stays 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; loose wiring connections in the ABS hydraulic valve body; ABS control unit malfunction. Solution: Loosen and retighten the grounding screw of the hydraulic valve body, cleaning the contact surface if necessary; check if the connector gap has widened; replace the ABS or ABS/ASR control unit. Condition 4: ABS warning light turns on during high-speed driving. Cause: The ABS control unit detects a significant difference between rear and front wheel speeds during high-speed driving; incorrect tire or wheel rim specifications. Solution: Refer to the vehicle's recommended tire and wheel rim specifications, usually found on the label near the fuel tank cap. Condition 5: ABS warning light intermittently turns on. Cause: Improper adjustment of the brake light switch; poor internal contact in the brake light. Solution: With the engine running, press the brake pedal and push the brake switch linkage down fully with your fingers, then release the pedal to complete self-positioning; replace the brake light switch if necessary. If the ABS warning light is on, it is advised not to continue driving. An illuminated ABS light indicates a fault in the vehicle's anti-lock braking system. During emergency braking, if the wheels lock up, the vehicle may skid uncontrollably, preventing the driver from slowing down or adjusting the vehicle's path, posing significant safety risks.

[DiBriella]

I also encountered the ABS light turning on while driving last time, and I felt a bit panicked since it's related to braking safety. Later, when I took it to the mechanic, it turned out that the wheel speed sensor was covered in mud, and cleaning it fixed the issue. The most common reasons for this light staying on are a dirty or faulty sensor, low brake fluid, or poor wiring connections. Actually, even if the light is on, the basic braking function still works, but you lose the anti-lock feature, making it easier to skid during sudden braking. So, don’t panic when you see this light—just find a place to check it out as soon as possible. Don’t ignore it, because safety is the top priority. When washing your car, pay attention to the area around the wheels to prevent the sensor from accumulating too much dust, and regularly checking the brake fluid is also quite necessary.