- Exhaust Gas Recirculation (EGR) circuit issues: The EGR circuit may have leaks, obstructions, or other faults preventing proper recirculation of exhaust gases.
- Faulty oxygen sensors: The oxygen sensors monitor the oxygen content in the exhaust gas and provide this information to the engine control unit (ECU) to adjust the air-fuel mixture. If an oxygen sensor becomes faulty, it can provide incorrect information to the ECU, affecting engine performance and triggering the depollution fault warning.
- Diesel Particulate Filter (DPF) problems: The DPF traps soot particles and other pollutants from the diesel engine's exhaust. If the DPF becomes clogged or damaged, it can restrict exhaust flow and lead to the depollution system fault warning.
- Catalytic Converter issues: The catalytic converter further reduces harmful emissions by converting pollutants like carbon monoxide and hydrocarbons into less harmful gases. If the catalytic converter becomes damaged or ineffective, it can result in the depollution fault warning.
- Turbocharger faults: In certain diesel vehicles, the turbocharger may be fitted with an electronic actuator. If this actuator fails, it can affect the turbocharger's operation, leading to a depollution system fault.
