U1947 – Lost Communication with the Hybrid Powertrain Control Module (HPCM).

The ODBII code U1947 indicates that there is a communication failure between the vehicle’s main control module and the Hybrid Powertrain Control Module (HPCM), which may affect the operation of the hybrid system.

The severity of ODBII code U1947 is typically considered moderate to severe, as it indicates a loss of communication with a critical component of the hybrid powertrain system.

Common Causes For: U1946 U1946: “Module Communication Failure”

• Faulty Hybrid Powertrain Control Module (HPCM)
• Damaged or corroded wiring or connectors
• Poor ground connections
• Failed communication network (CAN bus issues)
• Malfunctioning other control modules
• Software or firmware issues
• Battery or power supply problems

Common misdiagnosis for U1947 Lost Communication with the Hybrid Powertrain Control Module (HPCM)”.

• Faulty Hybrid Powertrain Control Module (HPCM)
• Wiring issues or damaged connectors
• Faulty Engine Control Module (ECM)
• Battery management system problems
• Communication network issues (CAN bus)
• Faulty sensors related to the hybrid system
• Software or firmware issues in the control modules
• Grounding issues in the electrical system

Common Troubleshooting Steps

When dealing with the OBD-II code U1947, which indicates “Lost Communication with the Hybrid Powertrain Control Module (HPCM),” there are several common troubleshooting steps you can follow to diagnose and potentially resolve the issue. Here’s a structured approach:

• Check for Additional Codes: Use an OBD-II scanner to check for any other trouble codes that may be present. Codes related to the HPCM or other modules can provide additional context.
• Inspect the Wiring and Connectors: **Visual Inspection: Check the wiring harness and connectors associated with the HPCM for any signs of damage, corrosion, or loose connections.
• **Connector Pins: Ensure that the pins in the connectors are not bent, corroded, or pushed back.
• Check Power and Ground: **Power Supply: Verify that the HPCM is receiving the correct voltage. Use a multimeter to check the power supply to the module.
• **Ground Connections: Ensure that the ground connections for the HPCM are secure and free of corrosion.
• Inspect the HPCM: If accessible, check the HPCM for any physical damage or signs of water intrusion.
• If the module is removable, consider reseating it to ensure a good connection.
• Check Communication Lines: Use a scan tool to check for communication between the HPCM and other modules. If other modules are not communicating, the issue may be with the communication bus (CAN bus).
• Inspect the CAN bus wiring for shorts, opens, or interference.
• Test the HPCM: If all connections and wiring appear to be in good condition, the HPCM itself may be faulty. Testing or replacing the module may be necessary.
• Some advanced scan tools can perform module tests to confirm functionality.
• Check for Software Updates: Verify if there are any software updates available for the HPCM or the vehicle’s ECU. Sometimes, communication issues can be resolved with a software update.
• Clear Codes and Test Drive: After performing the above checks and repairs, clear the trouble codes using the OBD-II scanner and take the vehicle for a test drive to see if the code returns.
• Consult Technical Service Bulletins (TSBs): Check for any TSBs related to the specific make and model of the vehicle. Manufacturers may have issued guidance on common issues related to the HPCM.
• Seek Professional Help: If the issue persists after performing these steps, it may be necessary to consult a professional mechanic or dealership for further diagnosis.Conclusion Troubleshooting OBD-II code U1947 involves a systematic approach to check for communication issues, wiring problems, and module functionality. Always ensure safety and follow manufacturer guidelines when working on vehicle electronics.