Symptom guide
Traction Control Light On
How to interpret a traction control warning and separate normal activation from a fault.
Quick answer
A flashing traction control light may be normal during wheel slip. A light that stays on can point to wheel speed sensors, ABS faults, steering angle data, or tire size issues.
Most likely causes
- Wheel speed sensor fault
- ABS system fault
- Mismatched tire sizes
- Steering angle sensor issue
- Low battery voltage event
Basic driver checks
- Notice whether the light flashes only on slippery roads.
- Check if the ABS light is also on.
- Confirm all tires are similar size and pressure.
- Scan ABS/traction control modules, not only engine codes.
DIY diagnostic path
- Check tire pressure and tire size first.
- Do not ignore combined ABS and traction warnings.
- Avoid aggressive driving until the fault is known.
- Record whether the light appeared after tire or brake work.
Common mistakes
- Assuming traction control is turned off intentionally
- Replacing sensors without checking wiring
- Ignoring mismatched tires
What to tell the mechanic
Ask for ABS live data and wheel speed sensor checks. Mention tire changes, battery work, or alignment work.