What is SPN 791 249 109
- SPN 791: Indicates a fault related to the fuel pressure sensor, pointing to an issue with fuel pressure readings.
- SPN 249: Refers to a fault in the air intake temperature sensor, suggesting issues with the intake air temperature data.
- SPN 109: Refers to a fault with the exhaust gas temperature sensor, indicating incorrect temperature data from the exhaust system.
Together, SPN 791 249 109 indicates multiple issues within the fuel, air intake, and exhaust systems that affect sensor data and can lead to poor engine performance.
Why It Happened
This fault code is commonly caused by:
- Malfunctioning sensors in the fuel, air intake, or exhaust systems.
- Wiring issues between the sensors and ECM.
- Contamination or corrosion in the sensor connectors.
- Blockages or restrictions in the fuel, air intake, or exhaust systems.
- ECM software issues affecting sensor data processing.
How to Resolve It
To resolve SPN 791 249 109:
- Inspect and test the fuel pressure sensor, air intake temperature sensor, and exhaust gas temperature sensor.
- Check for wiring damage, loose connections, or corrosion in the sensor circuits.
- Replace any faulty sensors and clean connectors if needed.
- Check the fuel, air intake, and exhaust systems for blockages or restrictions.
- After repairs, clear the fault code and restart the engine.
How to Avoid Before It Happens
To prevent SPN 791 249 109:
- Regularly inspect all related sensors and systems for damage or wear.
- Maintain clean and free-flowing fuel, air intake, and exhaust systems.
- Use a real-time monitoring tool like Clue to catch sensor issues early.
