What is SPN 103 FMI 1
- SPN 103: Refers to a fault related to the engine coolant temperature sensor, indicating that the coolant temperature is out of range.
- FMI 1: Indicates that the signal from the coolant temperature sensor is invalid or the data is too low for the ECM to process.
Together, SPN 103 FMI 1 signals that the engine coolant temperature sensor is not functioning properly, which could affect engine cooling and performance.
Why It Happened
This fault code is typically caused by:
- A malfunctioning or faulty coolant temperature sensor.
- Low coolant levels or coolant leaks.
- Wiring issues or loose connections between the sensor and ECM.
- A failing thermostat that is not regulating coolant flow properly.
How to Resolve It
To resolve SPN 103 FMI 1:
- Check the coolant level and top off if necessary.
- Inspect the engine coolant temperature sensor and replace it if faulty.
- Inspect the wiring and connectors for any damage or corrosion.
- Test the thermostat to ensure it is working correctly.
- After repairs, clear the fault code and restart the engine to verify the fix.
How to Avoid Before It Happens
To prevent SPN 103 FMI 1:
- Regularly inspect the coolant system and sensor.
- Maintain proper coolant levels and check for leaks.
- Use Clue to monitor engine temperature data and receive early alerts on sensor issues.
