What Causes the Chevrolet Engine Malfunction Light to Illuminate?

[Marian]

There are primarily 7 reasons for the engine malfunction light to illuminate: Sensor Failure: The sensors referred to here include coolant temperature, crankshaft position, air flow, intake air temperature, oxygen sensors, etc. When these sensors are damaged, have poor contact, or experience signal interruption, the vehicle's ECU cannot accurately obtain engine data, triggering the engine malfunction light. Fuel and Oil Quality Issues: Failure to add fuel and engine oil as required by the manufacturer may cause engine wear, leading to the malfunction light illuminating. Poor Mixture Combustion: Poor mixture combustion can result in engine carbon buildup or knocking. Once detected by the oxygen sensor and reported to the ECU, the malfunction light will illuminate as a warning. Spark plug failure, ignition coil failure, fuel pump failure, and fuel line blockages can all cause poor mixture combustion in the engine. Turbocharger Issues: The intake turbo piping and turbocharger can also cause the engine malfunction light to illuminate. The most common issue is turbocharger damage, accompanied by symptoms such as oil leaks, high oil consumption, reduced power, metallic noises, and blue or black smoke from the exhaust. Intake Issues: If the vehicle's intake system encounters problems, it may lead to engine piping blockages, and in severe cases, the engine malfunction light will illuminate. A dirty air filter that is not cleaned regularly can cause intake issues. Exhaust Issues: Exhaust faults can also trigger the engine malfunction light. Common causes include rear oxygen sensor failure, three-way catalytic converter failure, exhaust camshaft and bearing failure, with the three-way catalytic converter being the most frequent culprit. The use of leaded gasoline, lead or silicon-containing lubricant additives, physical damage to the catalytic converter, and fuel system failures can all easily lead to three-way catalytic converter issues. Anti-Theft System Failure: If the vehicle's electronic anti-theft system malfunctions or if the anti-theft controller does not match the engine electronic controller, the anti-theft system can prevent the engine from operating normally, causing the engine malfunction light to illuminate. If the engine malfunction light illuminates, follow these steps: First, check if the engine is running normally, looking for symptoms such as shaking or black smoke. If present, avoid restarting the engine. Note: Do not restart the engine if the red warning light is on. If the engine can be started, turn it off for 5-10 minutes. Without pressing the brake, press the start button once or turn the key halfway to the 'on' position without depressing the clutch. The vehicle will perform a self-check upon powering up. Wait 5-10 seconds to see if the malfunction light turns off. If the light remains on, visit a service center as soon as possible. The service center can use a portable diagnostic tool to read the fault code, identify the issue, and perform targeted repairs.