Circuit/System Description
WARNING: This page is about a different car, the 2019 Chevrolet Malibu. However, it is still accessible from the selected car via links, so may be relevant.
The exhaust gas heat recovery system utilizes an exhaust mounted air-to-liquid heat exchanger to transfer wasted energy (heat) from the exhaust to help warm the engine coolant faster. An exhaust-mounted dual-butterfly valve allows engine exhaust to either flow across the exchanger or to bypass the exchanger.
The hybrid/EV powertrain control module 2 controls the dual-butterfly valve actuator via Local Interconnect Network (LIN) data messaging.
A valve position learning process is performed once at the beginning of every ignition-ON key cycle. The hybrid/EV powertrain control module 2 commands the dual-butterfly valve actuator between fully closed and fully open, if the valve command is not close to the actual valve position this DTC is set.