A diagnostic scan can help point you toward the system that needs attention. It is especially useful when a vehicle has electronic or intermittent symptoms.
1. A warning light stays on
A check-engine, ABS, airbag or other warning light means the vehicle has detected something outside its expected range. A scan can retrieve the stored fault information.
2. The engine runs roughly
Misfiring, unstable idling, hesitation or reduced performance can be linked to ignition, fuel, airflow or sensor-related faults.
3. Fuel consumption suddenly increases
If your normal driving has not changed but fuel use has, the engine-management system may be compensating for a fault.
4. The problem comes and goes
Intermittent faults can be difficult to reproduce. Stored or pending codes may provide useful clues even when the symptom disappears.
5. A warning returns after a repair
If the same warning comes back, further diagnosis may be needed rather than simply clearing the code again.