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U code network Medium severity

U1202 SCP (J1850) Invalid or Missing Data for Windows

The OBD2 code U1202 SCP (J1850) indicates that there is invalid or missing data being communicated over the SCP (Serial Communication Protocol) network, which may affect the operation of certain vehicle systems, such as...

Definition

The OBD2 code U1202 SCP (J1850) indicates that there is invalid or missing data being communicated over the SCP (Serial Communication Protocol) network, which may affect the operation of certain vehicle systems, such as power windows

Common causes

  • Faulty or damaged wiring/connectors
  • Malfunctioning or disconnected sensors
  • Issues with the vehicle's communication network
  • Defective PCM (Powertrain Control Module)
  • Corrupted or missing data in the vehicle's computer
  • Problems with the SCP (Serial Communication Protocol) bus
  • Interference from aftermarket devices or modifications
  • Low battery voltage or poor electrical connections

Common misdiagnoses

  • Faulty Body Control Module (BCM)
  • Defective Window Motor or Regulator
  • Wiring Issues or Short Circuits
  • Corrupted Software or Firmware
  • Faulty Power Window Switch
  • Malfunctioning Instrument Cluster
  • Communication Issues with Other Modules
  • Battery or Charging System Problems

Troubleshooting steps

  1. 1. Check for Other Codes

    Use an OBD-II scanner to check for any other trouble codes that may be present. Addressing other codes may resolve the U1202 issue

  2. 2. Inspect the Wiring and Connectors

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

  3. 3. Repair or Replace

    Repair any damaged wires or connectors and ensure all connections are secure

  4. 4. Check the Battery and Ground Connections

    Ensure that the vehicle's battery is fully charged and that all ground connections are clean and secure. Poor ground connections can lead to communication issues

  5. 5. Test the Modules

    Module Functionality: Verify that the modules involved in the communication (e.g., PCM, BCM, ABS) are functioning correctly. This may involve using a scan tool to check for communication with each module

  6. 6. Reprogram or Replace

    If a specific module is found to be faulty, it may need to be reprogrammed or replaced

  7. 7. Inspect the OBD-II Port

    Check the OBD-II port for any damage or debris that could interfere with communication. Ensure that the port is clean and that the pins are not bent or corroded

  8. 8. Check for Interference

    Look for any aftermarket devices or modifications that may interfere with the vehicle's communication network. This includes alarms, remote starters, or other electronic devices

  9. 9. Perform a Network Test

    Use a professional scan tool to perform a network test to see if all modules are communicating properly. This can help identify which module is not responding

  10. 10. Clear Codes and Test Drive

    After performing the above checks and repairs, clear the trouble codes using the OBD-II scanner and take the vehicle for a test drive to see if the code reappears

  11. 11. Consult Technical Service Bulletins (TSBs)

    Check for any TSBs related to the U1202 code for your specific vehicle make and model. Manufacturers may have specific recommendations or known issues

  12. 12. Seek Professional Help

    If the issue persists after performing the above steps, it may be necessary to consult a professional mechanic or technician who has experience with OBD-II systems and can perform more advanced diagnostics. By following these troubleshooting steps, you should be able to identify and resolve the issue related to the U1202 code