U2990 – Lost Communication with Vehicle Control Module.

The ODBII code U2990 indicates a loss of communication with a specific vehicle control module, suggesting that the module is not responding or is unable to communicate with the vehicle’s network.

The severity of ODBII code U2990 is generally considered moderate to severe.

Common Causes For: U2989 Lost Communication with the Steering Angle Sensor.

• Faulty Vehicle Control Module (VCM)
• Damaged wiring or connectors
• Poor ground connections
• Corrupted software or firmware
• Faulty communication network (CAN bus issues)
• Low battery voltage
• Intermittent electrical connections
• Malfunctioning sensors or actuators

Common misdiagnosis for U2990 Lost Communication with Vehicle Control Module.

• Faulty wiring or connectors
• Defective vehicle control module (VCM)
• Issues with the powertrain control module (PCM)
• Malfunctioning body control module (BCM)
• Problems with the engine control module (ECM)
• Faulty sensors or actuators
• Battery or charging system issues
• Software or firmware glitches
• Grounding issues
• Communication network failures (CAN bus issues)

Common Troubleshooting Steps

When dealing with the OBD-II code U2990, which indicates “Lost Communication with Vehicle Control Module,” there are several common troubleshooting steps you can follow to diagnose and potentially resolve the issue. Here’s a structured approach:

• Check for Other Codes: Use an OBD-II scanner to check for any additional trouble codes. Sometimes, U2990 may be accompanied by other codes that can provide more context about the issue.
• Inspect the Wiring and Connectors: **Visual Inspection: Check the wiring harness and connectors related to the Vehicle Control Module (VCM) for any signs of damage, corrosion, or loose connections.
• **Connector Pins: Ensure that the pins in the connectors are not bent, corroded, or damaged.
• Check Power and Ground: **Power Supply: Verify that the VCM 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 VCM are secure and free of corrosion.
• Inspect the Vehicle Control Module: **Module Condition: Check the VCM for any physical damage or signs of water intrusion.
• **Reprogramming: If the module is suspected to be faulty, consider reprogramming or updating the software if applicable.
• Check for Communication Issues: **CAN Bus Communication: Use a scan tool to check if other modules in the vehicle are communicating properly. If other modules are also not communicating, there may be a problem with the CAN bus.
• **Network Integrity: Inspect the CAN bus wiring for shorts, opens, or other issues.
• Perform a Hard Reset: Disconnect the vehicle’s battery for a few minutes to reset the system. Reconnect and see if the code reappears.
• Test the VCM: If possible, test the VCM in another vehicle of the same make and model to determine if the module itself is faulty.
• 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 U2990.
• Seek Professional Help: If the issue persists after performing the above steps, it may be necessary to consult a professional mechanic or technician who has experience with the specific vehicle and its systems.Conclusion Troubleshooting OBD-II code U2990 involves a systematic approach to check for communication issues, inspect wiring and connections, and verify the functionality of the Vehicle Control Module. Always ensure safety precautions are taken when working on vehicle electronics.