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U code network Medium severity

U0252 Lost Communication With Lighting Control Module Rear "B

The OBD2 code U0252 indicates a loss of communication with the rear lighting control module "B," suggesting that the vehicle's diagnostic system is unable to communicate with that specific module

Definition

The OBD2 code U0252 indicates a loss of communication with the rear lighting control module "B," suggesting that the vehicle's diagnostic system is unable to communicate with that specific module

Common causes

  • Faulty Lighting Control Module
  • Damaged wiring or connectors
  • Poor ground connection
  • Corroded terminals
  • Short circuit in the wiring
  • Open circuit in the wiring
  • Malfunctioning Body Control Module (BCM)
  • Software issues or programming errors
  • Battery voltage issues
  • Intermittent connection issues

Common misdiagnoses

  • Faulty Lighting Control Module
  • Wiring issues or shorts
  • Faulty Body Control Module
  • Corroded connectors
  • Faulty rear lighting components
  • Battery or power supply issues
  • Faulty ground connections
  • Software or programming errors

Troubleshooting steps

  1. 1. Check for Other Codes

    Use an OBD-II scanner to check for any additional trouble codes. Sometimes, multiple codes can provide more context about the issue

  2. 2. Inspect Wiring and Connectors

    Visual Inspection: Check the wiring harness and connectors related to the rear lighting control module 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 pushed back

  4. 4. Test the Lighting Control Module

    Power and Ground: Verify that the lighting control module is receiving the correct power and ground signals. Use a multimeter to check voltage and ground continuity

  5. 5. Module Functionality

    If possible, test the module in another vehicle or replace it with a known good unit to see if the problem persists

  6. 6. Check for Communication Issues

    CAN Bus Integrity: Inspect the CAN bus wiring for shorts, opens, or high resistance. Use a multimeter or oscilloscope to check for proper communication signals

  7. 7. Other Modules

    Ensure that other modules on the CAN bus are functioning correctly, as a fault in another module can affect communication

  8. 8. Inspect Fuses

    Check the fuses related to the lighting control module and the rear lighting system. Replace any blown fuses and check if the code returns

  9. 9. Perform a Hard Reset

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

  10. 10. Software Updates

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

  11. 11. Scan Tool Functions

    Use a professional scan tool to perform active tests on the lighting control module. This can help determine if the module is responding correctly to commands

  12. 12. Consult Technical Service Bulletins (TSBs)

    Look for any TSBs related to the specific make and model of the vehicle. Manufacturers may have documented solutions for known issues

  13. 13. Seek Professional Help

    If the issue persists after performing the above steps, consider consulting a professional mechanic or automotive technician who has experience with electrical systems and can perform more advanced diagnostics. By following these steps, you should be able to identify the root cause of the U0252 code and take appropriate action to resolve the issue