What Causes the Engine Fault Yellow Light to Illuminate?
2 Answers
Engine fault yellow light illumination may be caused by sensor issues, maintenance problems, or engine component failures such as spark plug malfunction, ignition coil failure, fuel pump issues, or fuel line blockage. Below are two scenarios explaining the illumination of the engine fault yellow light: 1. Normal illumination: When the vehicle's power is turned on, the system performs a self-check. During this time, not only the engine yellow light but also other fault indicators will illuminate simultaneously before turning off, which is a normal process. 2. Abnormal illumination: If the engine fault yellow light remains on after starting the vehicle, this indicates that the ECU has detected a fault in the engine system, which is an abnormal condition.
When the check engine light comes on, I've researched this issue multiple times, and it's usually due to a problem with the emissions control system. Common causes include a faulty oxygen sensor, which monitors exhaust gases and may trigger false alarms if malfunctioning; a loose fuel system seal, such as a loose fuel cap, can also activate the warning; and aging ignition components, like worn-out spark plugs, which affect combustion efficiency. Additionally, a faulty catalytic converter or poor electrical connections can illuminate the light. If left unrepaired, this may impact engine performance, leading to sluggish acceleration or increased fuel consumption. I recommend purchasing an OBD2 scanner to read the trouble codes, which can pinpoint the issue accurately and save unnecessary expenses. Remember, this is just a warning—the car is still drivable—but get it checked soon to avoid bigger problems down the road.
