WOMS
P code powertrain Medium severity

P047E Exhaust Pressure Sensor "B" Circuit Intermittent/Erratic

The OBD2 code P047E indicates that there is an intermittent or erratic signal from the exhaust pressure sensor "B," which may affect the engine's performance and emissions control

Definition

The OBD2 code P047E indicates that there is an intermittent or erratic signal from the exhaust pressure sensor "B," which may affect the engine's performance and emissions control

Common causes

  • Faulty exhaust pressure sensor
  • Damaged wiring or connectors
  • Poor electrical connections
  • Exhaust leaks
  • Corroded terminals
  • Short circuits in the wiring
  • Faulty engine control module (ECM)
  • Intermittent sensor signal
  • Grounding issues

Common misdiagnoses

  • Faulty exhaust pressure sensor
  • Wiring issues or damaged connectors
  • Faulty turbocharger or wastegate
  • Exhaust leaks
  • Faulty engine control module (ECM)
  • Incorrectly installed or malfunctioning DPF (Diesel Particulate Filter)
  • Vacuum leaks
  • Faulty EGR (Exhaust Gas Recirculation) system components
  • Fuel system issues
  • Misinterpretation of related codes

Troubleshooting steps

  1. 1. Check for Additional Codes

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

  2. 2. Inspect the Exhaust Pressure Sensor

    Locate the exhaust pressure sensor (often referred to as "Sensor B") and visually inspect it for any signs of damage, corrosion, or loose connections

  3. 3. Ensure that the sensor is securely mounted and that the wiring harness is intact

  4. 4. Check Electrical Connections

    Inspect the wiring and connectors for the exhaust pressure sensor. Look for frayed wires, broken connectors, or signs of moisture intrusion

  5. 5. Ensure that all connections are clean and secure

  6. 6. Test the Exhaust Pressure Sensor

    Use a multimeter to test the resistance and voltage output of the exhaust pressure sensor according to the manufacturer's specifications

  7. 7. Compare the readings to the expected values in the service manual. If the readings are outside the specified range, the sensor may need to be replaced

  8. 8. Check for Vacuum Leaks

    Inspect the exhaust system for any leaks that could affect the pressure readings. A leak can cause erratic sensor readings

  9. 9. Use a smoke machine or soapy water to identify any leaks in the exhaust system

  10. 10. Inspect the Exhaust System

    Check for any blockages or restrictions in the exhaust system, such as a clogged catalytic converter or muffler, which could affect exhaust pressure

  11. 11. Check the Engine Control Module (ECM)

    Ensure that the ECM is functioning properly. Sometimes, a software update or reprogramming may be necessary

  12. 12. Check for any signs of water damage or corrosion in the ECM connectors

  13. 13. Clear Codes and Test Drive

    After performing the above checks and repairs, clear the trouble codes using the OBD-II scanner

  14. 14. Take the vehicle for a test drive to see if the code returns. Monitor the exhaust pressure sensor readings during the drive if possible

  15. 15. Consult Technical Service Bulletins (TSBs)

    Check for any TSBs related to the exhaust pressure sensor or the specific vehicle model. Manufacturers may have issued updates or fixes for known issues

  16. 16. Seek Professional Help

    If the issue persists after performing these steps, it may be necessary 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 and resolve the issue related to the P047E code. Always refer to the vehicle's service manual for specific procedures and specifications