If your vehicle is showing traction control or stability control light stays on, here are the most likely causes and the parts you'll need to fix each one.
The most common cause for this light. Wheel speed sensors sit at each wheel and are exposed to brake dust, road debris, and moisture, causing them to fail or send erratic signals to the traction control system.
If you recently had a wheel alignment, replaced steering components, or disconnected the battery, the steering angle sensor may have lost its center position. The stability control system disables itself if it doesn't know which way the steering wheel is pointed.
The wheel speed sensor reads a magnetic reluctor ring located inside the wheel bearing. If the bearing wears out and develops excessive play, the sensor loses its reading and triggers the traction control light.
Installing tires of different sizes, driving on a compact spare, or having severely uneven tire wear causes the wheels to rotate at different speeds. The system misinterprets this as constant wheel slip.
The traction control system relies on the brake pedal switch to know exactly when you are braking. If this switch fails, it can disable the stability system as a safety precaution.
The yaw sensor measures the vehicle's rotational movement and lateral acceleration. If it fails, the stability control system cannot detect if the car is sliding sideways and will disable itself.
The main computer that processes wheel speed and stability data can fail internally due to heat, vibration, or electrical shorts, disabling both ABS and traction control.