Why is the engine warning light on in the Teana?

[OReagan]

The engine warning light in the Teana may illuminate due to the following 7 main reasons: Sensor malfunction: This includes sensors such as coolant temperature, crankshaft position, air flow, intake temperature, and oxygen sensors. When these sensors are damaged, have poor connections, or experience signal interruptions, the vehicle's ECU cannot accurately obtain engine data, triggering the engine warning light. Fuel or oil quality issues: Failure to use the fuel or engine oil as specified by the manufacturer may cause engine wear, leading to the warning light. Poor combustion of the air-fuel mixture: Incomplete combustion can result in engine carbon buildup or knocking. When detected by the oxygen sensor and reported to the ECU, the warning light will illuminate as a warning. Issues such as faulty spark plugs, ignition coils, fuel pumps, or clogged fuel lines can cause poor combustion. Turbocharger problems: Issues with the intake boost piping or turbocharger can also trigger the engine warning light. 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. Intake problems: Blockages in the engine intake system can cause the warning light to come on. A dirty air filter that hasn't been cleaned regularly can lead to intake issues. Exhaust problems: Exhaust system faults, such as faulty rear oxygen sensors, catalytic converters, exhaust camshafts, or bearings, can trigger the warning light. The catalytic converter is the most common culprit. Using leaded gasoline, lead- or silicon-based lubricant additives, physical damage to the catalytic converter, or fuel system malfunctions can all contribute to catalytic converter failure. Anti-theft system malfunction: If the car's electronic anti-theft system fails or the anti-theft controller is incompatible with the engine control unit, the engine may not function properly, and the warning light will illuminate. If the engine warning light comes on, follow these steps: First, check if the engine is running normally. If there are issues like shaking or black smoke, avoid restarting the engine. Note: Never restart the engine if the red warning light is on. If the engine can be started, turn it off and wait 5-10 minutes. Without pressing the brake, press the start button once or turn the key halfway to the 'ON' position without engaging the clutch. The car will enter self-diagnosis mode. After 5-10 seconds, check if the warning light turns off. If the light remains on, visit a service center as soon as possible. Technicians can use a diagnostic tool to read the fault codes and perform targeted repairs.