What is SPN 2631 FMI 1
- SPN 2631: Refers to a fault related to the diesel particulate filter (DPF) pressure sensor, which measures the pressure difference across the DPF to monitor its condition and efficiency.
- FMI 1: Indicates that the sensor signal is below the expected range, meaning the ECM is receiving data from the DPF pressure sensor that is too low, which could indicate a problem with the sensor or DPF system.
Together, SPN 2631 FMI 1 suggests that the DPF system may be malfunctioning, which could cause improper exhaust filtration, reduced engine efficiency, and increased emissions if not addressed.
Why It Happened
This fault code is typically caused by:
- A malfunctioning or failed DPF pressure sensor.
- Blockages or excessive soot buildup in the DPF that affect pressure readings.
- A failure in the exhaust system components or sensors that prevent proper pressure measurement.
- Poor or incorrect sensor calibration, or a sensor that is not communicating properly with the ECM.
- Wiring issues, such as damaged connections, short circuits, or loose wires between the sensor and ECM.
How to Resolve It
To resolve SPN 2631 FMI 1:
- Inspect the DPF pressure sensor for any visible damage or faults, and replace it if necessary.
- Check for excessive soot buildup or blockages in the DPF system that may be causing inaccurate pressure readings.
- Inspect the wiring and connectors between the sensor and ECM for any damage, corrosion, or loose connections.
- Clean the DPF if necessary, or replace it if it is excessively clogged and cannot be cleaned.
- After repairs, clear the fault code and restart the engine to confirm that the issue has been resolved and that the DPF is functioning correctly.
How to Avoid Before It Happens
To prevent SPN 2631 FMI 1:
- Perform routine maintenance and cleaning of the DPF system to prevent soot buildup and ensure proper airflow.
- Regularly inspect the DPF pressure sensor and its wiring connections for any signs of wear or damage.
- Use an equipment management system like Clue to monitor DPF pressure data and receive alerts on abnormal readings before they become a serious problem.
