What is MID 21:
MID 21 refers to an issue with the Fuel Pressure Sensor Circuit. The ECM detects an abnormal signal from the fuel pressure sensor, which can affect fuel delivery and engine performance, leading to misfires, stalling, or poor acceleration.
Why This Happens:
- Faulty fuel pressure sensor.
- Shorted or damaged wiring in the sensor circuit.
- Loose or corroded sensor connectors.
- Low fuel pressure due to a malfunctioning fuel pump.
- ECM misinterpreting the sensor’s signal.
How to Fix It:
- Inspect the fuel pressure sensor for damage or malfunction.
- Test the sensor’s voltage and resistance to verify it matches manufacturer specifications.
- Check wiring and connectors for damage or corrosion.
- Replace the faulty fuel pressure sensor if necessary.
- Inspect the fuel system for any low pressure or pump issues.
How to Avoid It Before It Happens:
- Regularly inspect the fuel pressure sensor and wiring.
- Perform routine fuel system maintenance.
- Keep connectors clean and free from corrosion.
- Perform diagnostic checks to monitor fuel system health.
- Clue’s Fuel Management services monitor fuel pressure systems to detect issues before they affect engine operation.