What Causes the Malfunction Indicator Light to Illuminate?

[SanAsher]

Here are the reasons why the malfunction indicator light may illuminate: 1. Sensor issues: When the coolant temperature, crankshaft position, air flow, intake air temperature, or oxygen sensors are damaged, have poor connections, or experience signal interruptions, the vehicle's ECU cannot accurately obtain engine data; 2. Maintenance problems: Irregular maintenance and poor driving habits can increase the operational burden on the engine; 3. Fuel quality issues: The fuel used in the car has specific octane ratings, and failure to use the required grade can cause engine wear; 4. Poor fuel mixture combustion: This can lead to engine carbon buildup or knocking issues, which are detected by the engine's oxygen sensor; 5. False alarms: These may occur due to minor collisions during driving, tampering with engine connectors, or temporary ECU signal interruptions.