Is It Safe to Drive with the ABS Yellow Light On?

[SanElijah]

ABS fault light is on, it is recommended not to continue driving, because the ABS light indicates a malfunction in the vehicle's anti-lock braking system. During emergency braking, if the wheels lock up, the vehicle may lose control and skid, making it difficult for the driver to decelerate or adjust the vehicle's trajectory, posing significant safety risks. There are several states in which the ABS light may illuminate, with different causes and solutions for each state, as detailed below: State 1: ABS fault light remains constantly on (most common). Cause 1: The ABS speed sensor's sensing area 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 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 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 and turns off when accelerating. Cause: When multiple vehicle electrical devices are in use, the battery voltage drops below 10.5V. As the engine speed increases and the voltage rises, the ABS indicator light turns off. This may also occur if the ABS system's power supply voltage is too low, such as 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). State 3: The 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 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 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 label 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: With the engine running, depress the brake pedal, push the brake switch linkage down with your finger, then release the brake pedal to complete the self-setting position; replace the brake light switch if necessary.

[Bernice]

I've seen many cars with the ABS light on in yellow. If only the yellow light is on, the vehicle can usually still be driven because ABS is an auxiliary system, and the basic braking function remains intact. However, there is a significant safety risk. When ABS fails, the wheels are prone to locking up and skidding during hard braking, which is especially dangerous in rainy or slippery conditions. I once experienced this on the highway—I had to brake hard and almost rear-ended another car. Fortunately, I reacted quickly and avoided an accident. It's recommended to drive to a professional repair shop as soon as possible to diagnose the issue. Common causes include dirty wheel speed sensors or blown fuses. Don’t ignore this warning light and compromise driving safety. Regular maintenance of the braking system is also essential to prevent failures.