Why does the Jetta's ABS light come on when reaching 20 mph?
2 Answers
Reasons why the Jetta's ABS light comes on at 20 mph: Poor contact in the ABS hydraulic valve body grounding circuit; Poor contact in the ABS hydraulic valve body wire connector; ABS computer failure. How to handle it: Loosen the hydraulic valve body grounding fixing screw, then tighten the fixing screw and clean the contact surface if necessary; Check whether the plug gap has increased; Replace the ABS or ABS/ASR computer. If the ABS warning light comes on, it is recommended not to continue driving. Because the ABS light indicates a fault in the vehicle's anti-lock braking system, if the wheels lock during emergency braking, the vehicle will skid out of control, making it impossible for the driver to slow down or adjust the vehicle's trajectory, which poses a significant safety hazard. The role of ABS: To maximize the effectiveness of the brakes, shorten braking time and distance. It can effectively prevent vehicle skidding and fishtailing during emergency braking, ensuring good driving stability. It allows steering during emergency braking, providing good steering control. It avoids severe friction between the tires and the ground, reducing tire wear.
That day when I was driving my Jetta, the ABS light came on as soon as I reached 20 km/h, which felt unusual. I've encountered similar issues before, and I suspected it was a problem with the wheel speed sensor. These sensors, located near the wheels, are prone to dust buildup or damage from road debris. When the sensor signal is interrupted at a specific speed, like 20 km/h, it triggers the light and disables the ABS system. This can lead to wheel lock-up or skidding during braking, which is quite dangerous. Don't wait for it to fix itself—I immediately drove to the repair shop. The mechanic found that the left front wheel sensor was too dirty. A simple cleaning cost around a hundred bucks, and the problem was solved. During regular maintenance, pay extra attention to keeping the wheel area clean, especially in rainy seasons when mud and water can accumulate, to prevent sensor blockages that could affect driving safety. Ignoring this issue can increase fuel consumption and potentially lead to more serious problems, so it's best to address it early.
