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P code powertrain High severity

P1202 Injector Circuit Open / Shorted - Cylinder #2

The OBD2 code P1202 indicates a problem with the injector circuit for cylinder #2, specifically that the circuit is either open (disconnected) or shorted (electrically faulty), which can lead to improper fuel delivery...

Definition

The OBD2 code P1202 indicates a problem with the injector circuit for cylinder #2, specifically that the circuit is either open (disconnected) or shorted (electrically faulty), which can lead to improper fuel delivery to that cylinder

Common causes

  • Faulty fuel injector
  • Damaged wiring or connectors
  • Open circuit in the injector harness
  • Short circuit in the injector harness
  • Faulty engine control module (ECM)
  • Poor ground connection
  • Corroded or loose connectors

Common misdiagnoses

  • Faulty fuel injector
  • Wiring issues or damaged harness
  • Engine control module (ECM) failure
  • Ignition coil problems
  • Fuel delivery issues
  • Vacuum leaks
  • Faulty spark plugs or wires
  • Compression issues in the cylinder
  • Faulty crankshaft or camshaft position sensors
  • Injector driver circuit problems

Troubleshooting steps

  1. 1. Check for Additional Codes

    Use an OBD-II scanner to check for any other trouble codes that may be present. This can provide more context and help identify related issues

  2. 2. Visual Inspection

    Wiring and Connectors: Inspect the wiring and connectors leading to the injector for any signs of damage, corrosion, or loose connections. Pay special attention to the harness for Cylinder #2

  3. 3. Injector Connector

    Ensure that the connector for the injector is securely attached and free of debris

  4. 4. Test the Injector

    Resistance Test: Use a multimeter to measure the resistance of the injector. Compare the reading to the specifications provided in the vehicle’s service manual. A reading that is too high or too low may indicate a faulty injector

  5. 5. Injector Functionality

    If possible, perform a functional test of the injector by applying power directly to it to see if it opens and sprays fuel

  6. 6. Check the Power and Ground

    Power Supply: Use a multimeter to check if the injector is receiving the correct voltage when the ignition is on. Typically, you should see around 12 volts

  7. 7. Ground Circuit

    Ensure that the ground circuit for the injector is intact. A poor ground can cause the injector to not function properly

  8. 8. Inspect the Engine Control Module (ECM)

    ECM Functionality: If the wiring and injector are functioning correctly, the issue may lie with the ECM. Check for any signs of damage or corrosion in the ECM connectors

  9. 9. Reprogramming/Resetting

    In some cases, resetting the ECM or reprogramming it may resolve the issue

  10. 10. Check for Short Circuits

    Continuity Test: Perform a continuity test on the wiring harness to check for shorts to ground or other circuits. This can help identify if there is a short somewhere in the wiring

  11. 11. Inspect Related Components

    Fuel System: Check the fuel pump and fuel pressure regulator to ensure that they are functioning properly, as issues in the fuel system can sometimes trigger injector codes

  12. 12. Other Sensors

    Inspect related sensors (like the crankshaft position sensor or camshaft position sensor) that may affect injector operation

  13. 13. Clear Codes and Test Drive

    After performing the necessary repairs or checks, clear the trouble codes using the OBD-II scanner and take the vehicle for a test drive to see if the code returns

  14. 14. Consult a Professional

    If the issue persists after following these steps, it may be best to consult a professional mechanic or technician who has experience with your specific vehicle make and model. By following these troubleshooting steps, you should be able to identify the cause of the P1202 code and take appropriate action to resolve the issue