U2804 – Invalid Data Received from Vehicle Control Module.
The ODBII code U2804 indicates that the vehicle’s control module has received invalid or corrupted data from another control module, suggesting a communication issue within the vehicle’s network.
The severity of ODBII code U2804 is generally considered moderate.
Common Causes For: U2803 Control Module Communication Bus Off.
- Faulty Vehicle Control Module (VCM)
- Poor or damaged wiring/connectors
- Corrupted software or firmware in the VCM
- Communication issues between modules
- Low battery voltage or electrical issues
- Faulty sensors sending incorrect data
- Grounding issues in the electrical system
Common misdiagnosis for U2804 Invalid Data Received from Vehicle Control Module.
- Faulty Vehicle Control Module (VCM)
- Wiring issues or shorts in the communication lines
- Faulty sensors or actuators
- Incorrectly programmed or updated software
- Issues with the power supply to the VCM
- Problems with other control modules in the vehicle
- Corrupted data or communication errors between modules
Common Troubleshooting Steps
The OBD-II code U2804 indicates that there is an issue with the communication between the vehicle’s control modules, specifically that invalid data has been received from the vehicle control module. Here are some common troubleshooting steps to diagnose and resolve this issue:
- Check for Additional 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.
- Inspect Wiring and Connectors: Examine the wiring and connectors related to the vehicle control module. Look for signs of damage, corrosion, or loose connections that could affect communication.
- Check the Control Module: Ensure that the vehicle control module (VCM) is functioning properly. If possible, test the module in another vehicle or replace it with a known good unit to see if the problem persists.
- Inspect Ground Connections: Poor ground connections can lead to communication issues. Check the ground connections for the control modules and ensure they are clean and secure.
- Verify Power Supply: Ensure that the control module is receiving the correct voltage and that the power supply is stable. Use a multimeter to check the voltage at the module’s power supply pins.
- Check for Software Updates: Sometimes, the issue can be resolved with a software update. Check with the manufacturer or a dealership to see if there are any updates available for the control module.
- Clear Codes and Test Drive: After performing any repairs or checks, clear the trouble codes using the OBD-II scanner and take the vehicle for a test drive to see if the code returns.
- Scan for Communication Issues: Use a scan tool to monitor communication between modules. This can help identify if a specific module is not communicating properly.
- Inspect for Interference: Check for any aftermarket devices or modifications that may interfere with the vehicle’s communication network, such as alarms, remote starters, or other electronic devices.
- Consult Technical Service Bulletins (TSBs): Look for any TSBs related to the U2804 code for your specific vehicle make and model. Manufacturers may have specific recommendations or known issues that can help in troubleshooting. 1
- Professional Diagnosis: If the issue persists after performing the above steps, consider seeking help from a professional mechanic or dealership with experience in diagnosing communication issues. By following these steps, you should be able to identify and resolve the underlying cause of the U2804 code.