Circuit/System Description
WARNING: This page is about a different car, the 2017 Chevrolet Spark. However, it is still accessible from the selected car via links, so may be relevant.
The engine cooling fan system consists of a cooling fan assembly containing one electric cooling fan. The engine control module (ECM) uses two fan control circuits and a series of two relays to command the fan ON in either high speed or low speed, depending on cooling requirements. The ECM activates the applicable relay by grounding the control circuit with a solid state device called a driver. Each driver is equipped with a feedback circuit that is pulled-up to a voltage. The ECM can determine if the control circuit is open, shorted to ground or shorted to a voltage by monitoring the feedback voltage. In low speed, the fan is turned ON at a reduced speed. High speed has the fan turned ON at full speed.