What Causes the Engine Light to Turn On?

[NoahLynn]

Engine light may illuminate due to sensor issues, turbocharging problems, or exhaust system malfunctions. Below are the specific causes for the engine light turning on: Sensor Issues: Sensors such as coolant temperature, crankshaft position, air flow, intake air temperature, and oxygen sensors can trigger the engine light if they are damaged, have poor connections, or experience signal interruptions. When these sensors fail, the vehicle's ECU cannot accurately obtain engine data, leading to the illumination of the engine fault light. Turbocharging Problems: The intake boost piping and turbocharger can also cause the engine fault light to turn on. The most common issue is a damaged turbocharger, accompanied by symptoms like oil leaks, excessive oil consumption, reduced power, metallic noises, or blue/black smoke from the exhaust. Exhaust System Malfunctions: Components such as the rear oxygen sensor, catalytic converter, exhaust camshaft, and bearings can trigger the engine light. The most frequent cause is a faulty catalytic converter. Factors like using leaded gasoline, lead- or silicon-based lubricant additives, physical damage to the catalytic converter, or fuel system malfunctions can easily lead to catalytic converter failure.