WOMS
U code network Medium severity

U1085 SCP (J1850) Invalid or Missing Data for Powertrain Status Request

The OBD2 code U1085 SCP (J1850) indicates that there is invalid or missing data related to the powertrain status request, often due to communication issues between modules in the vehicle's network

Definition

The OBD2 code U1085 SCP (J1850) indicates that there is invalid or missing data related to the powertrain status request, often due to communication issues between modules in the vehicle's network

Common causes

  • Faulty or damaged wiring or connectors in the communication circuit
  • Malfunctioning powertrain control module (PCM)
  • Issues with the vehicle's data bus (SCP/J1850)
  • Faulty sensors or modules that are not communicating properly
  • Corrupted or outdated software in the PCM or other modules
  • Poor ground connections affecting communication
  • Intermittent electrical issues or shorts in the system

Common misdiagnoses

  • Faulty powertrain control module (PCM)
  • Wiring issues or damaged connectors
  • Faulty sensors (e.g., engine temperature, throttle position)
  • Communication issues between modules
  • Battery or charging system problems
  • Software or firmware issues in the PCM
  • Grounding issues
  • Faulty diagnostic tools or incorrect scan tool usage

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 Vehicle’s Wiring and Connectors

    Visual Inspection: Look for damaged, corroded, or loose connectors and wiring related to the powertrain control module (PCM) and other related modules

  3. 3. Ground Connections

    Ensure that all ground connections are secure and free of corrosion

  4. 4. Check the Powertrain Control Module (PCM)

    Connections: Ensure that the PCM connectors are secure and free of corrosion

  5. 5. Functionality

    If possible, test the PCM to ensure it is functioning correctly. This may require specialized equipment or professional assistance

  6. 6. Inspect the SCP (J1850) Communication Bus

    Bus Integrity: Check the integrity of the communication bus. Look for shorts, opens, or other issues in the wiring that could affect communication

  7. 7. Signal Quality

    Use an oscilloscope or a scan tool capable of monitoring live data to check the signal quality on the SCP bus

  8. 8. Check for Module Communication

    Ensure that all modules on the SCP bus are communicating properly. If one module is malfunctioning, it can affect the entire network

  9. 9. Use a scan tool to check if other modules are reporting data correctly

  10. 10. Inspect for Software Updates

    Check if there are any software updates available for the PCM or other related modules. Sometimes, manufacturers release updates to fix known issues

  11. 11. Perform a Hard Reset

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

  12. 12. Check for Environmental Factors

    Ensure that there are no external factors affecting the vehicle's performance, such as extreme temperatures or moisture that could impact electrical connections

  13. 13. Consult Technical Service Bulletins (TSBs)

    Look for any TSBs related to the specific make and model of the vehicle. Manufacturers may have documented common issues and fixes for this code

  14. 14. Professional Diagnosis

    If the issue persists after performing the above steps, consider seeking help from a professional mechanic or dealership. They may have access to advanced diagnostic tools and resources.Conclusion Troubleshooting OBD-II code U1085 involves a systematic approach to check for communication issues, inspect wiring and connectors, and ensure that all modules are functioning correctly. By following these steps, you can often identify the root cause of the problem and take appropriate action to resolve it