What is SPN 794 FMI 2:
SPN 794 FMI 2 refers to an issue with the Crankshaft Position Sensor circuit. FMI 2 indicates that the ECM is receiving a signal from the sensor that is outside the expected range, which can affect engine timing, causing stalling, misfires, or difficulty starting the engine.
Why This Happens:
- Faulty crankshaft position sensor.
- Damaged or shorted wiring in the sensor circuit.
- Loose or corroded sensor connectors.
- ECM misinterpretation of the sensor signal.
- Mechanical issues affecting crankshaft position readings.
How to Fix It:
- Inspect the crankshaft position sensor for damage or wear.
- Check wiring and connectors for damage or corrosion.
- Test the sensor’s voltage and resistance to ensure proper operation.
- Replace the faulty crankshaft position sensor if necessary.
- Ensure the ECM is receiving and processing signals correctly.
How to Avoid It Before It Happens:
- Regularly inspect the crankshaft position sensor and wiring.
- Keep connectors clean and free from corrosion.
- Perform routine diagnostic checks to monitor sensor performance.
- Verify that the ECM is receiving the correct data from the sensor.
- Clue’s Equipment Maintenance services help monitor sensor health and ensure early detection of issues to prevent engine timing problems.
