What is CID 904:
CID 904 refers to an issue with the vehicle's engine control system, specifically related to the crankshaft position sensor. The ECM detects a malfunction, which can cause poor engine performance or failure to start.
Why This Happens:
- Faulty crankshaft position sensor.
- Shorted or damaged wiring in the sensor circuit.
- Loose or corroded connectors.
- ECM failure to interpret sensor data correctly.
- Interference or power supply issues affecting the sensor.
How to Fix It:
- Inspect the crankshaft position sensor for damage or malfunction.
- Test the sensor’s voltage and resistance to ensure proper functionality.
- Check wiring and connectors for visible damage or corrosion.
- Replace the faulty sensor if necessary.
- Ensure stable power supply to the sensor and ECM communication.
How to Avoid It Before It Happens:
- Regularly inspect the crankshaft position sensor and wiring.
- Keep connectors clean and free from corrosion.
- Perform routine diagnostics to monitor sensor performance.
- Ensure stable power supply to the sensor and ECM communication.
- Clue’s equipment maintenance services track engine control systems and prevent sensor issues before they affect engine performance.
