The Best Check Engine Light Came On After Adding Coolant 2023. Your coolant warning light has come on, or has stayed on once you have started the car, because either your coolant levels are low, or your coolant is overheating. It is important to address this warning as soon as possible, as a low coolant level can lead to engine damage if not addressed.

Web if the check engine light is still on after filling coolant, the chances are that the coolant thermostat is stuck open or coolant temperature sensor is faulty. These explosions move the pistons up and down which, in very simple terms, starts to power your engine. Yes, low coolant levels in your car radiator can trigger the check engine light to come on.
