I got a 2012 Chevrolet Cruze 4 Cyl with engine code P0597, how can I fix this myself?
P0597 Engine coolant thermostat heater control circuit
Replace the thermostat,
You will have to remove the thermostat hose (ensure the coolant is drained) and remove the hose and the four bolts that attach to the thermostat housing.
Replace the thermostat, reinstall it in reverse order and fill it with coolant using a proper mixture with water. and ensure a proper coolant bleed.