1. Oxygen Sensor Issue: A faulty or malfunctioning oxygen sensor can trigger the CEL. The oxygen sensor monitors the amount of unburned oxygen in the exhaust gas, and if its readings are abnormal, it can indicate a problem with fuel efficiency or emissions.
2. Catalytic Converter Problem: Issues with the catalytic converter, which helps convert harmful pollutants into less harmful substances, can also cause the CEL to turn on. A damaged or inefficient catalytic converter can affect the vehicle's emission levels.
3. Engine Misfire: An engine misfire occurs when one or more cylinders fail to fire properly, resulting in incomplete combustion. Misfires can be caused by various factors such as ignition system problems, fuel injector issues, or compression problems.
4. Fuel System Issues: Problems with the fuel system, including a clogged fuel filter, faulty fuel injector, or malfunctioning fuel pump, can lead to an illuminated CEL. These issues can affect the fuel delivery and mixture, impacting the vehicle's performance and emission levels.
5. Emission Control System Malfunction: Any fault in the emission control system, such as a faulty EGR (Exhaust Gas Recirculation) valve, EVAP (Evaporative Emission Control) system problem, or a damaged vacuum line, can cause the CEL to turn on.
6. Faulty Sensors or Wiring: Malfunctioning sensors, such as the mass air flow sensor, crankshaft position sensor, or camshaft position sensor, can contribute to the CEL illumination. Issues with electrical connections, wiring, or relays related to engine or emission control systems can also be the cause.
7. Computer (ECU) Problems: If the Electronic Control Unit (ECU), which controls the vehicle's engine and other systems, detects an abnormality or problem within its parameters, it can trigger the CEL to come on as a warning.
It's crucial to address the Check Engine Light as soon as possible because it often indicates an issue that needs attention to prevent further damage or affect the vehicle's performance and emission compliance. If the CEL comes on in your Suzuki X90, it is recommended to have the vehicle diagnosed by a professional mechanic or an authorized service center to identify and rectify the underlying problem.
