What Causes the Yellow Engine Light on the Car Dashboard?

[DeJustin]

There are two main reasons why the yellow engine light appears on the car dashboard: the car's self-check when the power is turned on, and an actual engine malfunction. Self-check when the power is turned on: During this process, not only the yellow engine light but also other warning lights will illuminate briefly before turning off, which is a normal occurrence. Engine malfunction: If the yellow engine light remains on after starting the car, it indicates that the ECU (Engine Control Unit) has detected a fault. Possible issues include problems with sensors such as the coolant temperature sensor, crankshaft position sensor, mass air flow sensor, intake air temperature sensor, or oxygen sensor. When these sensors are damaged, have poor connections, or experience signal interruptions, the ECU cannot accurately obtain engine data, triggering the engine warning light. This is an abnormal condition. If the engine warning light stays on, you can try restarting and turning off the car three times in a row, or disconnect the negative terminal of the engine battery for 30 seconds before reconnecting it and attempting to start the car again. If the light persists, it is recommended to visit a 4S shop for professional inspection and repair.