U1202 – SCP (J1850) Invalid or Missing Data for Windows

The ODBII 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.

The severity of ODBII code U1202 SCP (J1850) Invalid or Missing Data is moderate.

Common Causes For: U1201 SCP (J1850) Invalid or Missing Data for Seat Motion / Control

• 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 misdiagnosis for U1202 SCP (J1850) Invalid or Missing Data for Windows

• 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

Common Troubleshooting Steps

The OBD-II code U1202 indicates that there is an issue with the communication between the vehicle’s modules, specifically related to the SCP (Serial Communication Protocol) using the J1850 protocol. This code typically means that the data being received is invalid or missing. Here are some common troubleshooting steps to diagnose and resolve the issue:

• 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.
• 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.
• **Repair or Replace: Repair any damaged wires or connectors and ensure all connections are secure.
• 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.
• 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.
• **Reprogram or Replace: If a specific module is found to be faulty, it may need to be reprogrammed or replaced.
• 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.
• 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.
• 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.
• 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.
• 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.
• 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.