When to act urgently
A flashing light, severe shaking, smoke or loss of power warrants stopping and arranging assistance.
Common possible causes
- Sensor or wiring fault
- Ignition misfire
- Fuel or air measurement issue
- Emissions-system concern
What you can safely check
- Check the fuel cap is secure
- Note changes in sound or performance
- Avoid clearing codes before diagnosis
What not to attempt
Avoid dismantling safety-critical, pressurised, hot or high-voltage systems without suitable training and equipment. Generic symptoms are not enough to choose a repair.
How a workshop diagnoses it
A technician will confirm the symptom, review relevant vehicle information and use physical, electronic or measured tests as appropriate. The aim is to separate the underlying cause from related symptoms.