What are the reasons for the ABS warning light to illuminate after vehicle inspection?
2 Answers
The reasons for the ABS warning light to illuminate after vehicle inspection are: 1. Air in the system pipeline; 2. System computer malfunction; 3. Vehicle speed sensor failure; 4. ABS wiring harness breakage. The working principle of ABS is: during emergency braking, the highly sensitive wheel speed sensors installed on each wheel detect wheel lock-up, and the computer controls the pressure regulator to release pressure from the wheel's brake cylinder, preventing wheel lock-up. The functions of the ABS system are: 1. To prevent vehicle loss of control, increase braking distance, and improve vehicle safety; 2. To enhance the overall braking performance of the vehicle; 3. To prevent wheel lock-up during braking; 4. To ensure that the driver can control the direction during braking and prevent rear axle skidding.
A few days ago, the ABS light in my car suddenly came on after the annual inspection. I quickly recalled the inspection process—they might have touched the wiring of the wheel speed sensors while checking the brake system. These sensors are installed inside the wheel hubs, and removing the wheels can easily loosen them or get them covered in dust, causing signal interruption and triggering the light. Another common reason is the frequent brake testing during the inspection, which may not give the system enough time to reset, leading the ECU to misjudge a fault. It’s also possible that an aging fuse connection was blown by the current surge during testing. If this happens, I recommend going to a repair shop immediately for a check-up instead of driving hastily, as ABS failure increases the risk of skidding during emergency braking. That’s how I handled it last time—the technician scanned the system with a computer, secured the wiring harness, and resolved the issue, saving me from future troubles.
