U1375 – Invalid Data Received from the Transmission Control Module (TCM).
The ODBII code U1375 indicates that the Engine Control Module (ECM) has received invalid or corrupted data from the Transmission Control Module (TCM), which may affect vehicle performance and transmission operation.
The severity of ODBII code U1375 is generally considered moderate to severe.
Common Causes For: U1374 Communication Bus Off.
- Faulty Transmission Control Module (TCM)
- Poor electrical connections or wiring issues
- Corrupted data communication between TCM and other modules
- Software or firmware issues in the TCM
- Faulty sensors related to transmission operation
- Low transmission fluid levels or quality
- Malfunctioning engine control module (ECM)
- Grounding issues in the vehicle’s electrical system
Common misdiagnosis for U1375 Invalid Data Received from the Transmission Control Module (TCM).
- Faulty Transmission Control Module (TCM)
- Wiring issues or short circuits in the transmission harness
- Faulty Engine Control Module (ECM)
- Incorrectly calibrated or faulty sensors (e.g., speed sensors)
- Transmission fluid issues (low fluid, contamination)
- Faulty or damaged connectors
- Software or firmware issues in the TCM or ECM
- Mechanical transmission problems (e.g., slipping, internal damage)
Common Troubleshooting Steps
The OBD-II code U1375 indicates that the Engine Control Module (ECM) has received invalid data from the Transmission Control Module (TCM). This can be caused by various issues, including communication problems, wiring issues, or faults within the TCM itself. Here are some common troubleshooting steps to diagnose and resolve the issue:
- 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.
- Inspect Wiring and Connectors: **Visual Inspection: Check the wiring harness and connectors between the ECM and TCM for any signs of damage, corrosion, or loose connections.
- **Repair or Replace: If any issues are found, repair or replace the damaged wiring or connectors.
- Check for Software Updates: **Manufacturer Updates: Check if there are any software updates available for the ECM or TCM from the vehicle manufacturer. Sometimes, software bugs can cause communication issues.
- Test the TCM: **Functionality Check: Use a scan tool to check the TCM for any internal faults or issues. If the TCM is malfunctioning, it may need to be repaired or replaced.
- **Communication Test: Verify that the TCM is communicating properly with the ECM. This can often be done with a professional scan tool.
- Inspect Ground Connections: Ensure that all ground connections related to the ECM and TCM are secure and free of corrosion. Poor ground connections can lead to communication issues.
- Check Power Supply: Verify that the TCM is receiving the correct voltage and ground. Use a multimeter to check the power supply to the TCM.
- Clear Codes and Test Drive: After performing any repairs or inspections, 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 U1375 code for your specific vehicle make and model. Manufacturers may have specific recommendations or known issues.
- Professional Diagnosis: If the issue persists after performing the above steps, consider seeking help from a professional mechanic or dealership. They may have access to specialized diagnostic tools and knowledge of specific vehicle issues.
- Replace the TCM (if necessary): If all other troubleshooting steps fail and the TCM is determined to be faulty, it may need to be replaced. Ensure that the replacement TCM is compatible with your vehicle. By following these steps, you should be able to identify and resolve the issue causing the U1375 code. Always refer to the vehicle’s service manual for specific procedures and specifications.