What are the reasons for the engine warning light in Peugeot 308?

[GabrielFitz]

There are mainly 7 reasons for the engine warning light in Peugeot 308: Sensor failure: The sensors mentioned here include water temperature, crankshaft position, air flow, intake temperature, oxygen sensor, etc. When these sensors are damaged, have poor contact, or signal interruption, the car's ECU cannot accurately obtain engine data, which will cause the engine warning light to come on. Fuel quality issues: If fuel and engine oil are not added as required by the manufacturer, it may cause engine wear and trigger the warning light. Poor mixture combustion: Poor mixture combustion can lead to engine carbon deposits or knocking. When detected by the oxygen sensor and reported to the ECU, the warning light will illuminate as a warning. Spark plug failure, ignition coil failure, fuel pump failure, and fuel line blockage can all cause poor mixture combustion in the engine. Turbocharging issues: The intake turbocharging pipeline and turbocharger can also cause the engine warning light to come on. The most common issue is turbocharger damage, accompanied by symptoms such as oil leaks, high oil consumption, reduced power, metal noises, and blue or black smoke from the exhaust pipe. Intake issues: If there is a problem with the car's intake, it may cause engine pipeline blockage, and in severe cases, trigger the engine warning light. A dirty air filter that is not cleaned regularly can lead to intake problems. Exhaust issues: Exhaust faults can also cause the engine warning light to come on. The rear oxygen sensor, three-way catalytic converter, exhaust camshaft, and bearing failures are all causes of exhaust problems, with the three-way catalytic converter being the most common. Using leaded gasoline, lead or silicon-containing lubricant additives, physical damage to the three-way catalytic converter, or engine fuel supply system failures can easily cause three-way catalytic converter issues. Anti-theft system failure: If the car's electronic anti-theft system malfunctions, or if the anti-theft controller does not match the engine electronic controller, the anti-theft system can also prevent the engine from working properly and trigger the engine warning light. If the engine warning light comes on, follow these steps: First, check if the engine is running normally and if there are issues such as shaking or black smoke. If so, avoid restarting the engine. Especially note that if the red light is on, do not restart the engine. If the engine can be started, turn it off for 5-10 minutes, then without pressing the brake, press the start button once or turn the key halfway to the 'on' position without pressing the clutch. The car will perform a self-check after powering on. Wait for 5-10 seconds and observe if the warning light on the dashboard goes off. If the warning light does not go off, visit a service station as soon as possible to diagnose the issue. The service station can use a portable diagnostic tool to read the fault code, obtain fault information, and perform targeted repairs.

[VanPresley]

I think the engine warning light coming on is quite common, especially in cars like the Peugeot 308. The most frequent cause is sensor issues, such as a faulty temperature sensor or oxygen sensor, which detects abnormal engine operation. Unstable fuel supply, clogged injectors, or a malfunctioning fuel pump can also lead to poor combustion, triggering the light when emissions exceed standards. Programming errors in the control module can activate the warning, as can aging circuits or loose connections. From my personal experience driving similar cars, I've found it's best not to drive immediately but to pull over and check the oil pressure and battery status first. Ignoring it might just increase fuel consumption, but in severe cases, there's a risk of stalling mid-drive. I recommend promptly visiting a professional workshop to read the fault codes with a diagnostic tool to identify the exact issue before repairs.