What Causes the ABS Light to Stay On?
2 Answers
ABS light stays on due to: 1. Damaged wheel speed sensor triggering ABS warning, causing the ABS sensor to fail detecting wheel rotation speed; 2. Contaminated wheel speed sensor making ABS warning light illuminate; 3. Faulty wheel speed sensor wiring requiring harness replacement. A constantly lit ABS light doesn't affect normal braking or cause brake failure, but disables ABS functionality during emergency braking. The ABS system automatically modulates brake force during deceleration to prevent wheel lock-up, maintaining optimal tire-road adhesion by keeping wheels in a rolling-sliding state (with approximately 20% slip ratio).
Last time when I was driving, the ABS light kept staying on. This issue commonly occurs when the wheel speed sensor is faulty or blocked by dirt, preventing the car from detecting the wheel rotation speed, which triggers the system alarm. It could also be due to loose or corroded wire connectors, especially prone to problems during rainy or snowy weather. Without ABS, the anti-lock braking function is lost, and the wheels may lock up during braking, which is particularly dangerous on slippery roads. For inspection, I can first check if there's mud around the wheel speed sensor and clean it off to see if that helps. If not, I can try replacing the fuse by opening the fuse box—it's a simple operation. However, if the light remains on, it's necessary to visit a repair shop to read the fault codes with a diagnostic computer. Don't delay for too long to avoid major issues affecting safety. If it's beyond your capability, don't force a fix—professional diagnosis saves both hassle and money.
