Malfunction in the thermostat control system. The on-board computer reports problems with communication with the control unit, so a possible cause may be poor contact. The cooling system circuit is open, which may affect the operation of the power unit as a whole.Engine started, engine running, and the PCM detected a high voltage present at the PCM for 3 minutes after the engine started. The Starter Relay Control Circuit High Voltage test monitors the voltage signal that is sent from the ignition switch.