If your airbag or SRS warning light stays illuminated after starting the vehicle, the right approach is to diagnose the restraint-system fault before attempting to reset it. In most vehicles,...

If your check-engine light appeared because of an oxygen-sensor-related fault, “resetting the O2 sensor” can mean several different things. You might want to clear a diagnostic trouble code...

A starter relay is a small component, but it sits at an important crossroads in the vehicle’s starting circuit. When it begins to fail, the result can range from a completely silent start attempt...

A failing thermostat can create two very different problems: an engine that runs too hot or one that stays too cold for too long. The most common bad thermostat symptoms include overheating, slow...

A transmission rarely fails without leaving clues. Slipping, delayed engagement, harsh shifting, shuddering, unusual noises, fluid leaks, burning smells, warning lights, and difficulty selecting...

A catalytic converter can fail without announcing itself in one unmistakable way. Depending on whether the catalyst has lost chemical efficiency, become contaminated, suffered internal damage, or...