What is SPN 973 FMI 9
- SPN 973: Refers to a fault related to the air intake temperature sensor, which measures the temperature of the air entering the engine.
- FMI 9: Indicates that the signal from the air intake temperature sensor is invalid, out of range, or improperly calibrated, meaning the ECM is receiving faulty data from the sensor.
When SPN 973 FMI 9 appears, it signals that the ECM cannot process the air intake temperature data correctly, which could affect the air-fuel mixture and engine performance.
Why It Happened
This fault code is typically caused by:
- A malfunctioning or faulty air intake temperature sensor.
- Loose or damaged wiring connections between the sensor and ECM.
- Contamination or corrosion in the sensor or its connectors.
- Environmental factors, such as extreme temperatures, affecting the sensor's ability to provide accurate readings.
- A failure in the ECM that prevents it from processing the sensor data correctly.
How to Resolve It
To resolve SPN 973 FMI 9:
- Inspect the air intake temperature sensor for faults or damage and replace it if necessary.
- Check the wiring and connectors for any damage, corrosion, or loose connections.
- Ensure that environmental factors are not causing extreme temperature readings, and clean the sensor if needed.
- After repairs, clear the fault code and restart the engine to confirm the fix.
How to Avoid Before It Happens
To prevent SPN 973 FMI 9:
- Regularly inspect the air intake system and the air intake temperature sensor.
- Ensure the air intake is free from debris and contamination.
- Monitor intake air temperature data with Clue to catch any issues early before they lead to performance problems.
