U2122 – Instrument Cluster Communication Failure

The ODBII code U2122: Instrument Cluster Communication Failure indicates a loss of communication between the instrument cluster and other control modules in the vehicle, which may affect the functionality of the dashboard displays and gauges.

The severity of ODBII code U2122: Instrument Cluster Communication Failure is generally considered moderate.

Common Causes For: U2121 U2121: Instrument Cluster Communication Failure

• Faulty instrument cluster
• Damaged wiring or connectors
• Poor ground connections
• Failed communication module
• Corroded terminals
• Software issues or glitches
• Faulty CAN bus communication
• Malfunctioning sensors or components linked to the cluster

Common misdiagnosis for U2122 U2122: Instrument Cluster Communication Failure

• Faulty instrument cluster
• Bad wiring or connectors
• Defective body control module (BCM)
• Malfunctioning engine control module (ECM)
• Issues with the CAN bus system
• Power supply problems
• Faulty sensors or actuators
• Software glitches or updates needed
• Grounding issues
• Intermittent electrical faults

Common Troubleshooting Steps

The OBD-II code U2122 indicates an “Instrument Cluster Communication Failure.” This code typically suggests that there is a communication issue between the instrument cluster and other modules in the vehicle’s network. 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. Other codes can provide additional context for the issue.
• Inspect Wiring and Connectors: Visually inspect the wiring and connectors related to the instrument cluster. Look for signs of damage, corrosion, or loose connections.
• Pay special attention to the wiring harness that connects the instrument cluster to the vehicle’s network.
• Check for Ground Issues: Ensure that the instrument cluster has a good ground connection. A poor ground can lead to communication failures.
• Use a multimeter to check for continuity between the ground point and the instrument cluster.
• Test the Instrument Cluster: If possible, test the instrument cluster itself. This may involve bench testing or swapping it with a known good unit to see if the problem persists.
• Check for any signs of internal failure, such as burned components or damaged circuit boards.
• Inspect Other Modules: Check other modules in the vehicle that communicate with the instrument cluster. This includes modules like the Body Control Module (BCM), Engine Control Module (ECM), and Transmission Control Module (TCM).
• Ensure that these modules are functioning correctly and are not causing communication issues.
• Check for Software Updates: Verify if there are any software updates available for the vehicle’s modules. Sometimes, communication issues can be resolved with a software update.
• Perform a Network Test: Use a scan tool to perform a network test to see if all modules are communicating properly. This can help identify if the issue is isolated to the instrument cluster or if it affects other modules as well.
• Inspect Fuses: Check the fuses related to the instrument cluster and communication network. A blown fuse can interrupt communication.
• Clear Codes and Test Drive: After performing any repairs or inspections, clear the trouble codes and take the vehicle for a test drive to see if the code returns.
• Consult Service Manual: Refer to the vehicle’s service manual for specific diagnostic procedures and wiring diagrams related to the instrument cluster and communication network.1
• Seek Professional Help: If the issue persists after performing these steps, consider seeking help from a professional mechanic or dealership with experience in diagnosing and repairing communication issues. By following these troubleshooting steps, you can systematically identify and resolve the cause of the U2122 code.