U0064: Vehicle Communication Bus E

Definition

The OBD2 code U0064 indicates a communication issue on the Vehicle Communication Bus, specifically related to the "E" module, which may be experiencing a loss of communication or a malfunction

Common causes

Faulty communication module
Damaged wiring or connectors
Short circuit in the communication bus
Open circuit in the communication bus
Faulty control module
Poor ground connection
Interference from aftermarket devices
Software issues or bugs in the control modules

Common misdiagnoses

Faulty Engine Control Module (ECM)
Defective Body Control Module (BCM)
Bad wiring or connectors
Malfunctioning Transmission Control Module (TCM)
Issues with other communication modules
Battery or charging system problems
Faulty sensors or actuators
Software or firmware issues in modules

Troubleshooting steps

1. Check for Other Codes

Start by scanning the vehicle for any other diagnostic trouble codes (DTCs). Other codes may provide additional context or indicate which module is having communication issues
2. Inspect Wiring and Connectors
3. Visually inspect the wiring and connectors associated with the Vehicle Communication Bus E. Look for signs of damage, corrosion, or loose connections
4. Pay special attention to the connectors on the modules that communicate over Bus E
5. Check for Short Circuits
6. Use a multimeter to check for short circuits in the wiring. Ensure that there are no unintended connections between the communication wires and ground or power
7. Test the Modules
8. Identify the modules that are connected to Bus E. These may include the engine control module (ECM), transmission control module (TCM), or other body control modules
9. Check if the modules are functioning properly. If one module is faulty, it may disrupt communication on the bus
10. Inspect the Bus Termination
11. Ensure that the bus is properly terminated. Some communication buses require termination resistors at each end. If these are missing or faulty, it can cause communication issues
12. Check for Interference
13. Look for any aftermarket devices or modifications that may interfere with the communication bus. This includes alarm systems, stereo systems, or other electronic devices
14. Perform a Network Test
15. Use a scan tool capable of performing a network test to check the communication between modules. This can help identify which module is not responding
16. Update Software/Firmware
17. Check if there are any software or firmware updates available for the vehicle’s control modules. Sometimes, communication issues can be resolved with an update
18. Clear Codes and Test Drive
19. After performing the above checks and repairs, clear the codes and take the vehicle for a test drive to see if the code returns
20. Refer to the vehicle’s service manual for specific wiring diagrams and troubleshooting procedures related to the communication bus. 1
21. Seek Professional Help
22. If the issue persists after performing these steps, it may be necessary to consult a professional mechanic or technician who has experience with vehicle communication systems. By following these steps, you should be able to identify and resolve the issue related to the U0064 code

Definition

Common causes

Common misdiagnoses

Troubleshooting steps

1. Check for Other Codes

2. Inspect Wiring and Connectors

3. Visually inspect the wiring and connectors associated with the Vehicle Communication Bus E. Look for signs of damage, corrosion, or loose connections

4. Pay special attention to the connectors on the modules that communicate over Bus E

5. Check for Short Circuits

6. Use a multimeter to check for short circuits in the wiring. Ensure that there are no unintended connections between the communication wires and ground or power

7. Test the Modules

8. Identify the modules that are connected to Bus E. These may include the engine control module (ECM), transmission control module (TCM), or other body control modules

9. Check if the modules are functioning properly. If one module is faulty, it may disrupt communication on the bus

10. Inspect the Bus Termination

11. Ensure that the bus is properly terminated. Some communication buses require termination resistors at each end. If these are missing or faulty, it can cause communication issues

12. Check for Interference

13. Look for any aftermarket devices or modifications that may interfere with the communication bus. This includes alarm systems, stereo systems, or other electronic devices

14. Perform a Network Test

15. Use a scan tool capable of performing a network test to check the communication between modules. This can help identify which module is not responding

16. Update Software/Firmware

17. Check if there are any software or firmware updates available for the vehicle’s control modules. Sometimes, communication issues can be resolved with an update

18. Clear Codes and Test Drive

19. After performing the above checks and repairs, clear the codes and take the vehicle for a test drive to see if the code returns

20. Refer to the vehicle’s service manual for specific wiring diagrams and troubleshooting procedures related to the communication bus. 1

21. Seek Professional Help

22. If the issue persists after performing these steps, it may be necessary to consult a professional mechanic or technician who has experience with vehicle communication systems. By following these steps, you should be able to identify and resolve the issue related to the U0064 code