1. Emission Control System Issues: Faults or malfunctions within the emission control system, such as the oxygen sensor, catalytic converter, or evaporative emission control system, can trigger the CEL.
2. Engine Performance Issues: Problems related to engine performance, such as misfires, ignition system faults, or fuel injection system issues, can also lead to the illumination of the CEL.
3. Exhaust Gas Recirculation (EGR) System: Defects within the EGR system, which is responsible for recirculating exhaust gases to reduce emissions, can cause the CEL to turn on.
4. Turbocharger Problems: Issues with the turbocharger or its components, including boost pressure regulation or turbocharger failure, can activate the CEL.
5. Electrical Issues: Electrical malfunctions, such as faulty sensors, wiring problems, or malfunctioning electrical components, can trigger the CEL.
6. Transmission Issues: In automatic transmission models, transmission-related issues, such as solenoid failures or transmission control module problems, can cause the CEL to illuminate.
7. Engine Control Unit (ECU): Faults or software problems within the ECU, which controls various engine and vehicle functions, can lead to the CEL being turned on.
8. Catalytic Converter: Failure of the catalytic converter, which helps convert harmful exhaust emissions into less harmful substances, can also result in the CEL being activated.
It's important to note that the specific reason for the CEL illumination can only be determined through diagnostic procedures using a specialized Volvo diagnostic tool or scanner. If the CEL is on, it's advisable to have the vehicle checked by a qualified technician or a Volvo dealership to identify and address the underlying issue promptly.
