The diagnostic code P0597 OBD2 has to do with a failure in the electronically controlled engine thermostat system. It indicates that the control voltage is non-existent. The thermostat has several load temperature sensors.
The function of the thermostat heater is to control the flow of coolant, in addition to regulating the operating temperature of the engine. The Engine Control Module (ECM) supplies 12 volts to the thermostat.
In case the ECM detects an incorrect signal from the thermostat, the DTC code P0597 OBD II is set.