Why does the ABS light come on after inspection?

[VanAlina]

After inspection, the ABS light comes on because during the exhaust gas test, only the two front wheels are rotating while the rear wheels remain stationary. Each wheel is equipped with an ABS sensor that continuously monitors the wheel speed. Under normal driving conditions, the rotation speeds of the front and rear wheels cannot differ significantly. However, when only the front wheels rotate for an extended period while the rear wheels remain stationary, the ABS system may mistakenly interpret this as a system malfunction and immediately illuminate the warning light to alert the driver for inspection. The Anti-lock Braking System, abbreviated as ABS, functions to automatically regulate the braking force during vehicle deceleration, preventing wheel lock-up and maintaining a state of rolling with slight slip (around 20% slip ratio). This ensures optimal traction between the wheels and the road surface.