Thermostat Monitor

THERMOSTAT MONITOR

The thermostat monitor is designed to verify correct thermostat operation. The thermostat checks for a thermostat that is operating correctly by estimating engine coolant temperature on calibrated parameters of engine fueling and ambient temperature. The thermostat compares the actual engine coolant temperature to the expected calibrated engine temperature. If the actual engine coolant temperature is not within the calibrated value expected temperature, a DTC sets and the malfunction indicator lamp (MIL) is illuminated. This monitor is executed once per drive cycle.