What Causes the Peugeot 408's Central Display to Show an Engine Fault?
2 Answers
Peugeot 408's central display showing an engine fault is caused by poor combustion state, poor fuel quality, unclean engine cylinder interior, and carbon deposits. Poor Combustion State: Poor engine combustion state is the main reason for the engine fault light to illuminate. In automotive design, to ensure the engine operates in good condition and maintains a normal working lifespan, oxygen sensors are installed to monitor the engine's combustion state. Once the combustion state deteriorates, it not only pollutes the environment but also leads to fuel wastage and excessive engine wear. Poor Fuel Quality: The engine has specific requirements for fuel quality indicators, especially as regulations increasingly demand higher performance from engines. In practice, some gas stations cannot fully comply with these standards to provide fuel that meets the requirements of high-performance engines, resulting in the engine fault light illuminating. Unclean Engine Cylinder Interior and Carbon Deposits: After a certain period of use, carbon deposits accumulate inside the engine. These deposits alter the engine's design parameters and, due to their unstable nature and heat retention, can cause uncontrolled ignition, leading to engine knocking. In such cases, the engine fault light will also illuminate. Solutions for Engine Faults: Engine Cleaning: Once the engine fault light comes on, the driver should promptly visit a repair shop to clean the carbon deposits using specialized cleaning agents. Using Higher Octane Fuel: After cleaning the engine, since most cars compliant with China's National IV emission standards have a compression ratio above 10.0, they are not suitable for long-term use of gasoline below 95 octane. To maintain the engine's good working condition, drivers can opt for 95 or 97 octane gasoline, which usually resolves the issue of the engine fault light illuminating.
I've been repairing cars for over a decade, and there are quite a few common reasons why the Peugeot 408's engine warning light comes on. It could be sensor issues, like the oxygen sensor detecting excessive emissions or the coolant temperature sensor failing, sending error signals to the computer. It might also be due to a clogged emission system, such as a blocked or leaking catalytic converter, reducing efficiency. In terms of the fuel system, worn-out spark plugs or faulty ignition coils causing irregular ignition can trigger the light. Other possibilities include low oil pressure, loose electrical connections, or relay failures. Sometimes, the computer software needs an update to resolve error codes. I recommend not delaying—take it to a reliable repair shop to use an OBD scanner to quickly pinpoint the issue. Delaying repairs could lead to higher costs later. Regular maintenance and checking wear-prone parts can help extend the engine's lifespan.
