U1928: U1928: "Module Communication Failure

Definition

The OBD2 code U1928 indicates a "Module Communication Failure," meaning that there is a problem with communication between the vehicle's control modules, which may affect their ability to exchange data properly

Common causes

Faulty wiring or connectors
Failed or malfunctioning control module
Poor ground connections
Corroded or damaged pins in connectors
Communication network issues (e.g., CAN bus problems)
Software or firmware issues in modules
Intermittent electrical connections
Low battery voltage or power supply issues

Common misdiagnoses

Faulty wiring or connectors
Defective control module
Software issues or updates needed
Power supply problems
Grounding issues
Intermittent communication issues
Other module failures
Corrupted data or configuration errors

Troubleshooting steps

1. Check for Other Codes

Use an OBD-II scanner to check for any other trouble codes that may be present. Sometimes, multiple codes can provide more context for the issue
2. Inspect Wiring and Connectors
3. Visually inspect the wiring and connectors associated with the affected module. Look for signs of damage, corrosion, or loose connections
4. Pay special attention to the ground connections, as poor grounding can lead to communication issues
5. Check Power Supply
6. Ensure that the affected module is receiving the proper voltage. Use a multimeter to check the power supply to the module
7. Verify that the fuses related to the module are intact and functioning
8. Test the Module
9. If possible, test the affected module to ensure it is functioning correctly. This may involve using specialized diagnostic tools or swapping the module with a known good one
10. Check for Interference
11. Look for any aftermarket devices or modifications that may interfere with the communication network, such as alarms, remote starters, or other electronic accessories
12. Inspect the CAN Bus
13. If the vehicle uses a Controller Area Network (CAN) bus, check for issues with the bus itself. This may involve checking for short circuits, open circuits, or other faults in the wiring
14. Use a CAN bus diagnostic tool to monitor the communication on the bus
15. Reset the Modules
16. Sometimes, simply resetting the modules can resolve communication issues. This can be done by disconnecting the battery for a few minutes or using a scan tool to clear the codes
17. Update Software/Firmware
18. Check if there are any software or firmware updates available for the vehicle's modules. Sometimes, communication issues can be resolved with an update
19. Consult Technical Service Bulletins (TSBs)
20. Look for any TSBs related to the specific make and model of the vehicle. Manufacturers may have issued guidance on known communication issues
21. Professional Diagnosis
22. If the issue persists after performing the above steps, it may be necessary to seek professional assistance. A qualified technician can perform more advanced diagnostics and repairs. By following these steps, you can systematically identify and address the underlying cause of the U1928 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 affected module. Look for signs of damage, corrosion, or loose connections

4. Pay special attention to the ground connections, as poor grounding can lead to communication issues

5. Check Power Supply

6. Ensure that the affected module is receiving the proper voltage. Use a multimeter to check the power supply to the module

7. Verify that the fuses related to the module are intact and functioning

8. Test the Module

9. If possible, test the affected module to ensure it is functioning correctly. This may involve using specialized diagnostic tools or swapping the module with a known good one

10. Check for Interference

11. Look for any aftermarket devices or modifications that may interfere with the communication network, such as alarms, remote starters, or other electronic accessories

12. Inspect the CAN Bus

13. If the vehicle uses a Controller Area Network (CAN) bus, check for issues with the bus itself. This may involve checking for short circuits, open circuits, or other faults in the wiring

14. Use a CAN bus diagnostic tool to monitor the communication on the bus

15. Reset the Modules

16. Sometimes, simply resetting the modules can resolve communication issues. This can be done by disconnecting the battery for a few minutes or using a scan tool to clear the codes

17. Update Software/Firmware

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

19. Consult Technical Service Bulletins (TSBs)

20. Look for any TSBs related to the specific make and model of the vehicle. Manufacturers may have issued guidance on known communication issues

21. Professional Diagnosis

22. If the issue persists after performing the above steps, it may be necessary to seek professional assistance. A qualified technician can perform more advanced diagnostics and repairs. By following these steps, you can systematically identify and address the underlying cause of the U1928 code