What Causes the ABS Light to Illuminate on Snowy Days?

[MacHolden]

ABS light illumination can occur in various states, each with different causes and solutions as follows: State 1: ABS warning light remains constantly on (most common). Cause 1: The ABS wheel speed sensor's sensing area is covered by mud, sludge, or other contaminants, affecting its ability to detect the corresponding speed signal. This prevents the ABS computer from determining the vehicle speed or 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 transmission due to loose system wiring connections or faulty ABS relay contacts. Solution: Inspect 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, battery voltage drops below 10.5V. The light turns off as engine speed increases and voltage rises. This may also occur due to insufficient ABS system power supply voltage caused by poor terminal contact or grounding issues. Solution: Check battery specific gravity; inspect charging system; examine power supply (e.g., voltage relay or poor power contact). State 3: ABS warning light remains on after engine start until engine IGFF. Cause: Poor grounding contact of ABS hydraulic valve body; poor electrical connector contact of ABS hydraulic valve body; ABS computer malfunction. Solution: Loosen and retighten the hydraulic valve body ground screw, cleaning contact surfaces if necessary; check for enlarged connector gaps; replace ABS or ABS/ASR computer. State 4: ABS warning light illuminates during high-speed driving. Cause: ABS computer detects excessive difference between rear and front wheel speed signals during high-speed driving; incorrect tire or wheel rim specifications. Solution: Refer to vehicle's tire and wheel rim specifications, checking label near fuel tank cap. State 5: ABS warning light intermittently illuminates. Cause: Improper brake light switch adjustment; poor internal contact of brake light. Solution: With engine running, press brake pedal fully, manually push brake switch linkage downward to its limit, then release pedal to complete self-positioning; replace brake light switch if needed. When the ABS warning light is on, it's recommended to avoid continued driving as it indicates a malfunction in the anti-lock braking system. During emergency braking, locked wheels may cause loss of vehicle control and skidding, preventing the driver from decelerating or adjusting the vehicle's path, posing significant safety risks.