WOMS
U code network High severity

U0273 Lost Communication with Hybrid Powertrain Control Module (HPCM) A

The OBD2 code U0273 indicates a loss of communication with the Hybrid Powertrain Control Module (HPCM) A, which may affect the vehicle's hybrid system functionality

Definition

The OBD2 code U0273 indicates a loss of communication with the Hybrid Powertrain Control Module (HPCM) A, which may affect the vehicle's hybrid system functionality

Common causes

  • Faulty Hybrid Powertrain Control Module (HPCM)
  • Damaged or corroded wiring or connectors
  • Poor ground connections
  • Failed communication network (CAN bus issues)
  • Malfunctioning battery management system
  • Software or firmware issues in the HPCM
  • Faulty sensors related to the hybrid system
  • Low battery voltage or power supply issues

Common misdiagnoses

  • Faulty wiring or connectors
  • Defective Hybrid Powertrain Control Module (HPCM)
  • Issues with the Engine Control Module (ECM)
  • Battery or charging system problems
  • Faulty sensors related to the hybrid system
  • Software or firmware issues in the control modules
  • Problems with the vehicle's communication network (CAN bus)

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. Inspect the Wiring and Connectors

    Visual Inspection: Check the wiring harness and connectors related to the HPCM for any signs of damage, corrosion, or loose connections

  3. 3. Connector Pins

    Ensure that the pins in the connectors are not bent, corroded, or pushed back

  4. 4. Check Power and Ground

    Verify that the HPCM is receiving the correct voltage and ground. Use a multimeter to check for proper voltage at the module's power and ground terminals

  5. 5. Test the HPCM

    If possible, perform a functional test of the HPCM. This may require specialized diagnostic equipment or software

  6. 6. If the module is suspected to be faulty, consider replacing it or testing it in another vehicle if available

  7. 7. Inspect the CAN Bus

    The HPCM communicates over the Controller Area Network (CAN) bus. Check for issues in the CAN bus wiring, including shorts, opens, or interference

  8. 8. Use a scan tool to monitor the CAN bus for communication errors

  9. 9. Check for Software Updates

    Verify if there are any software updates available for the HPCM or the vehicle’s main control module. Sometimes, manufacturers release updates to fix communication issues

  10. 10. Clear Codes and Test Drive

    After performing inspections and repairs, clear the trouble codes and take the vehicle for a test drive to see if the code returns

  11. 11. Consult Technical Service Bulletins (TSBs)

    Check for any TSBs related to the specific make and model of the vehicle. Manufacturers may have documented common issues and fixes for the U0273 code

  12. 12. Seek Professional Help

    If the issue persists after performing the above steps, it may be necessary to consult a professional mechanic or a dealership with experience in hybrid vehicles.Additional Considerations

  13. 13. Battery Health

    Ensure that the vehicle's battery is in good condition, as low voltage can affect module communication

  14. 14. Environmental Factors

    Sometimes, environmental factors like moisture or extreme temperatures can affect module performance. By following these steps, you should be able to identify the root cause of the U0273 code and take appropriate action to resolve the issue