Traction control light

Flashing, this symbol means traction control is actively working — cutting power or braking a spinning wheel to keep the car pointing where you aimed it. Steady, it means the system is unavailable, either because it was switched off or because of a fault.

• The system switched off by the driver, sometimes by accident
• A wheel speed sensor fault
• An ABS fault, because both systems read the same sensors
• Tyres of mismatched size or very uneven wear

Flashing: ease off the accelerator. The surface has less grip than you are asking for, and the car is telling you so as it happens.

Steady: check whether the system has been switched off by mistake. If it has not, drive with a wider margin, particularly in rain or on loose surfaces.

If it stays on with the system switched on, and especially if the ABS light is on as well — that combination usually points at a shared sensor.