Group 28 Troubleshooting MID 128 PID 110 Coolant Temperature 25 Type of fault: FMI Description: Fault Condition: Possible Symptoms: Possible Cause:
FMI 0 • Data valid but above normal operational range • The Engine Coolant Temperature (ECT) Sensor is indicating an unphysical value • Malfunction indicator lamp illuminated • Extreme driving condition • Faulty coolant thermostat • Malfunctioning fan • Blocked radiator FMI 2 • Data erratic, intermittent or incorrect • The Engine Coolant Temperature (ECT) Sensor output is too high or too low • May affect driveability in extreme cases • Malfunction indicator lamp illuminated • Faulty Engine Coolant Temperature (ECT) Sensor or Engine Management System (EMS) Module connector • Break in Engine Coolant Temperature (ECT) Sensor harness • Malfunctioning Engine Coolant Temperature (ECT) Sensor FMI 4 • Voltage below normal or shorted low • N/A • Difficult to start in cold climates • Idle run regulation is deteriorated • Malfunction indicator lamp illuminated • Internal fault in the Engine Coolant Temperature (ECT) Sensor harness • Faulty Engine Coolant Temperature (ECT) Sensor connector • Faulty Engine Coolant Temperature (ECT) Sensor FMI 5 • Current below normal or open circuit • N/A • Difficult to start in cold climates • Idle run regulation is deteriorated • Malfunction indicator lamp illuminated • An open in the Engine Coolant Temperature (ECT) Sensor circuit • An open in the Engine Coolant Temperature (ECT) Sensor • Intermittent fault in the Engine Coolant Temperature (ECT) Sensor • Faulty Engine Coolant Temperature (ECT) Sensor connector • Faulty Engine Coolant Temperature (ECT) Sensor FMI 10 • Abnormal rate of change • The Engine Coolant Temperature (ECT) Sensor output is showing a constant value • May affect vehicle driveability • Faulty Engine Coolant Temperature (ECT) Sensor harness • Engine Coolant Temperature (ECT) Sensor failure