What Causes the Car Engine Light to Illuminate?

[StJulia]

Engine light illumination can be caused by sensor issues, turbocharging problems, or exhaust system malfunctions. Below are the specific reasons for the engine light turning on: Sensor Issues: Sensors such as coolant temperature, crankshaft position, air flow, intake temperature, and oxygen sensors may trigger the engine warning light when damaged, poorly connected, or experiencing signal interruptions. In such cases, the vehicle's ECU cannot accurately obtain engine data. Turbocharging Problems: Issues with the intake boost piping or turbocharger can also cause the engine light to illuminate. The most common problem is turbocharger damage, often accompanied by symptoms like oil leaks, excessive oil consumption, reduced power, metallic noises, or blue/black smoke from the exhaust. Exhaust System Problems: Faults in components like the rear oxygen sensor, catalytic converter, exhaust camshaft, or bearings may activate the engine light. The most frequent cause is catalytic converter failure, often resulting from using leaded gasoline, lead/silicon-based lubricant additives, physical damage to the converter, or fuel system malfunctions.