Start with the symptom.
Choose what your car is doing. See the common causes, simple checks you can make safely, and when you should stop driving.
This tool gives general guidance, not a confirmed diagnosis.
Choose a symptom to see likely causes, safe checks, and when to stop driving.
Diagnose before buying parts
The same symptom can have several causes. These checks help avoid an expensive guess.
A code is a clue—not a parts order
Read the exact OBD-II code, inspect the affected system, and test the likely cause before replacing a sensor.
New battery, same problem
Charging-system or cable faults can drain a new battery. Test battery health, alternator output, and voltage drop.
Adding refrigerant repeatedly
Low refrigerant usually means a leak. Pressure and leak testing should come before expensive component replacement.
Ignoring a new grinding sound
Metal-on-metal wear can turn a pad service into a rotor or caliper repair and can reduce stopping ability.
Looking only at tread depth
Also check pressure, sidewall bulges, cracks, uneven inner-edge wear, and the tire's age.
Opening a hot radiator cap
Hot pressurized coolant can cause severe burns. Shut down, wait for full cooling, then inspect safely.
Useful next reads
Why car A/C is not cold
Separate refrigerant, airflow, electrical, fan, and compressor symptoms.
Read guide →A/C compressor cost factors
Understand parts, labor, refrigerant service, and related repairs.
Read guide →Compare repair quotes
Check labor, parts quality, diagnostic fees, warranties, and required work.
Read guide →