WOMS
U code network High severity

U1135 Lost Communication with Instrument Panel Cluster (IPC) Control Module

The OBD2 code U1135 indicates a loss of communication between the vehicle's control module and the Instrument Panel Cluster (IPC) control module, suggesting a potential issue with wiring, connectors, or the IPC itself

Definition

The OBD2 code U1135 indicates a loss of communication between the vehicle's control module and the Instrument Panel Cluster (IPC) control module, suggesting a potential issue with wiring, connectors, or the IPC itself

Common causes

  • Faulty Instrument Panel Cluster (IPC) Control Module
  • Damaged wiring or connectors
  • Poor ground connection
  • Faulty communication network (CAN bus issues)
  • Blown fuse related to IPC
  • Corroded terminals
  • Software or firmware issues in the IPC
  • Malfunctioning body control module (BCM)

Common misdiagnoses

  • Faulty Instrument Panel Cluster (IPC)
  • Wiring issues or shorts in the communication lines
  • Faulty Body Control Module (BCM)
  • Power supply issues to the IPC
  • Faulty or corroded connectors
  • Software or firmware issues in the IPC or BCM
  • Faulty CAN bus communication
  • Issues with other modules on the network

Troubleshooting steps

  1. 1. 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

  2. 2. Inspect the Wiring and Connectors

    Visual Inspection: Check the wiring harness and connectors related to the IPC for any signs of damage, corrosion, or loose connections

  3. 3. Connector Pins

    Ensure that the pins in the connectors are not bent, corroded, or damaged

  4. 4. Check Power and Ground

    Verify that the IPC is receiving the correct voltage and ground. Use a multimeter to check for proper voltage at the IPC connector

  5. 5. Check the ground connections to ensure they are secure and free of corrosion

  6. 6. Inspect the IPC Module

    If possible, remove the IPC module and inspect it for physical damage or signs of water intrusion

  7. 7. If the IPC is removable, consider testing it in another vehicle (if available) to confirm its functionality

  8. 8. Check for Communication Issues

    Use a scan tool to check if the IPC is communicating with other modules in the vehicle. If other modules are also not communicating, the issue may be with the communication bus (CAN bus)

  9. 9. Inspect the CAN bus wiring for shorts, opens, or interference

  10. 10. Test the Vehicle’s Battery and Charging System

    A weak battery or poor charging system can cause communication issues. Ensure the battery is fully charged and the alternator is functioning properly

  11. 11. Look for Software Updates

    Check if there are any software updates available for the IPC or the vehicle’s control modules. Sometimes, manufacturers release updates to fix communication issues

  12. 12. Perform a Hard Reset

    Disconnect the vehicle’s battery for a few minutes to reset the modules. Reconnect and see if the code reappears

  13. 13. Check for Aftermarket Modifications

    If any aftermarket accessories or modifications have been made to the vehicle, they could interfere with the IPC communication. Temporarily remove or disconnect them to see if the issue resolves

  14. 14. Consult Technical Service Bulletins (TSBs)

    Look for any TSBs related to the IPC or communication issues for your specific vehicle make and model. Manufacturers may have documented common issues and solutions.1

  15. 15. Professional Diagnosis

    If the issue persists after performing the above steps, it may be necessary to consult a professional mechanic or dealership for further diagnosis. They may have specialized tools and knowledge to address complex communication issues. By following these steps, you should be able to identify the root cause of the U1135 code and take appropriate action to resolve it