How to check BMW Coolant Level - Low Warning Dec 19, 2018Would BMW low coolant level trigger engine light? No. Low coolant level warning should not turn on service engine soon or check engine light. Unless the coolant system is almost empty in which case the engine temperature sensor may malfunction triggering the check engine light.Author: YOUCANIC Symptoms of a BMW Engine Overheating | It Still Runs A coolant-warning-light will illuminate on your BMW's onboard computer display when the engine-coolant level is low. If the engine is not receiving enough coolant, it will overheat. If the coolant-warning-light is illuminated in your instrument panel, your engine is likely going to overheat soon.