ABS fault light is on, it is recommended not to continue driving, because the ABS light on means that the vehicle's anti-lock braking system is faulty. During emergency braking, if the wheels lock up, the vehicle will lose control and skid, making it impossible for the driver to slow down or adjust the vehicle's trajectory, posing significant safety hazards. There are various states of the ABS light being on, with different causes and solutions for each state, as detailed below: State 1: ABS fault light stays on (most common). Cause 1: The ABS speed sensor sensing part is covered by mud, sludge, 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 on the speed sensor and adjust the gap between the speed sensor and the signal ring to restore normal function. Cause 2: Poor signal due to loose connections between system lines or poor contact of the ABS relay, leading to system failure. Solution: Check the line connections and reconnect any loose parts. State 2: ABS warning light intermittently lights up and turns off when accelerating. Cause: When multiple vehicle electrical devices are used, the battery voltage drops below 10.5V. As the engine speed increases and the voltage rises, the ABS indicator light turns off. The ABS system power supply voltage is too low, possibly due to poor terminal contact or grounding issues. Solution: Check the battery specific gravity; inspect the charging system; examine the power supply (e.g., voltage relay or poor power contact). State 3: ABS warning light stays on after engine start and only turns off when the engine is turned off (IGFF). Cause: Poor grounding contact of the ABS hydraulic valve body; poor contact of the ABS hydraulic valve body wire connector; ABS computer failure. Solution: Loosen the grounding screw of 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 comes on during high-speed driving. Cause: During high-speed driving, the ABS computer detects a significant difference 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 lights up. Cause: Improper adjustment of the brake light switch; poor internal contact of the brake light. Solution: Start the engine, press the brake pedal, push the brake switch linkage down to the bottom with your finger, then release the brake pedal to complete the self-setting position; replace the brake light switch.
