What is the reason for the ABS light turning on and then off after restarting?

[BradleyRose]

ABS light turning on and then off after restarting may be an intermittent fault. The reasons why it does not light up after restarting are as follows: 1. The vehicle has not moved, and the system components have not detected any abnormal data from the sensors. 2. No fault code has been triggered, so there is no current fault code, and the light does not illuminate. Reasons for the ABS light staying on: 1. The current working condition method for exhaust emission testing requires loading the two front wheels, so the vehicle's two front wheels are placed on the rollers of the testing equipment to "drive." 2. The vehicle's ABS control unit can receive normal wheel speed signals from the two front wheels but detects zero speed signals from the two rear wheels. The ABS control unit determines this as an abnormal driving condition, so the ABS system will follow the program to illuminate the ABS light and deactivate the ABS function.

[McDavid]

I've encountered many cases where the ABS light stays on after startup but turns off after a restart. This is mostly caused by dust accumulation on the wheel speed sensor leading to signal interruption or loose wiring harness causing self-check failure—the error light turns on when the system starts up. After a restart, the circuit may stabilize and pass the self-check, causing the light to turn off. For example, after driving in rainy or dusty conditions, the sensor gets covered in mud, increasing electronic interference. It's like a computer freezing and needing a restart—it's an intermittent issue that shouldn't be ignored. ABS failure during emergency braking can easily lead to skidding and loss of control. I recommend regularly cleaning around the wheels, using a high-pressure water spray to rinse the sensor area. If it happens frequently, visit a repair shop to use a diagnostic tool for deeper troubleshooting. Safety is no small matter—the cost of inspection and repair is low and worth the investment.

[LaHarrison]

Having driven for over a decade, I've frequently encountered ABS warning lights that turn off after restarting in older vehicles. My previous car once had its ABS light illuminate on bumpy roads, which disappeared after a restart. It turned out to be due to an oxidized and loose sensor connector causing intermittent contact issues that triggered the system alarm; the light would go off after restarting when the connection was restored. Such temporary faults can be caused by vibrations, moisture, or voltage fluctuations—never ignore them to save trouble. When the ABS light is on, the ABS function might be disabled, significantly increasing the risk during emergency braking. A quick self-check for debris or loose wiring around the wheels can help, but it's best to visit a professional shop for a comprehensive test to prevent minor issues from escalating into major repairs. Driving safety is paramount—addressing problems promptly is far better than regretting them after an accident.

[PrestonAnn]

The ABS light coming on at startup and turning off after restart is usually due to a transient sensor fault or system self-check error. Possible causes include dirty sensors blocking signals, loose wiring causing power interruption, or short-term electronic module interference. For example, unstable voltage during cold starts may trigger false alarms, and the light turns off after restart when voltage stabilizes. Safety note: When the light is on, ABS may not function, risking wheel lockup during emergency braking. For self-inspection, clean wheel sensors with a damp cloth and secure wiring harness connectors; frequent occurrences require professional diagnosis and repair.