U1847 – Instrument Cluster Communication Failure
The ODBII code U1847: 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 cluster and related systems.
The severity of ODBII code U1847: Instrument Cluster Communication Failure is generally considered moderate to severe.
Common Causes For: U1846 U1846: “BCM Communication Failure”
- Faulty instrument cluster
- Damaged wiring or connectors
- Poor ground connections
- Failed communication module
- Corrupted software or firmware
- Short circuit in the communication line
- Issues with the vehicle’s CAN bus system
- Malfunctioning sensors or components connected to the cluster
Common misdiagnosis for U1847 U1847: Instrument Cluster Communication Failure
- Faulty instrument cluster
- Bad wiring or connectors
- Malfunctioning body control module (BCM)
- Defective engine control module (ECM)
- Issues with the CAN bus system
- Low battery voltage or poor battery connections
- Faulty sensors or actuators related to the cluster
- Software glitches or programming errors
Common Troubleshooting Steps
The OBD-II code U1847 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 related trouble codes. This can provide more context and help identify if other modules are also experiencing communication issues.
- 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 by connecting a known good unit. This can help determine if the issue lies within the cluster itself.
- Some vehicles may allow for self-diagnostics of the instrument cluster; refer to the service manual for specific procedures.
- Inspect the CAN Bus: The instrument cluster typically communicates over the Controller Area Network (CAN) bus. Check for any issues with the CAN bus wiring, such as shorts or opens.
- Use an oscilloscope or CAN bus diagnostic tool to monitor the communication signals on the bus.
- Check Other Modules: Since the instrument cluster communicates with other modules, check those modules for faults. Look for codes or issues in modules like the Body Control Module (BCM) or Engine Control Module (ECM).
- Ensure that all modules are powered and functioning correctly.
- Update Software/Firmware: Check if there are any software updates available for the vehicle’s modules. Sometimes, communication issues can be resolved with a software update.
- Reset the System: After performing repairs or inspections, clear the trouble codes using the OBD-II scanner and see if the code returns after a test drive.
- Consult Service Manual: Refer to the vehicle’s service manual for specific diagnostic procedures related to the instrument cluster and communication systems.
- Seek Professional Help: 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 cause of the U1847 code.