U1207 – SCP (J1850) Invalid or Missing Data for Primary Id

The ODBII code U1207 SCP (J1850) indicates that there is invalid or missing data from the primary identifier in the vehicle’s communication network, which may affect the operation of various systems.

The severity of ODBII code U1207 is moderate.

Common Causes For: U1206 U1206: “Speed Control Module Communication Loss”

• Faulty or damaged wiring/connectors
• Malfunctioning control modules
• Poor ground connections
• Communication network issues
• Corrupted data or software glitches
• Incompatible or faulty aftermarket devices
• Low battery voltage or power supply issues
• Interference from other electronic devices

Common misdiagnosis for U1207 SCP (J1850) Invalid or Missing Data for Primary Id

• Faulty ABS module
• Defective engine control module (ECM)
• Bad wiring or connectors
• Malfunctioning body control module (BCM)
• Incorrectly programmed or flashed modules
• Faulty communication lines
• Issues with the vehicle’s battery or charging system
• Problems with the instrument cluster

Common Troubleshooting Steps

The OBD-II code U1207 indicates that there is an issue with the communication on the SCP (Serial Communication Protocol) bus, specifically related to the J1850 protocol. This code typically means that the vehicle’s control module is not receiving valid data from a primary module, which can lead to various performance issues. Here are some common troubleshooting steps to diagnose and resolve the U1207 code:

• Check for Additional Codes: Use an OBD-II scanner to check for any other trouble codes that may be present. Addressing other codes may resolve the U1207 issue.
• Inspect the Wiring and Connectors: **Visual Inspection: Check the wiring harnesses and connectors related to the affected modules for any signs of damage, corrosion, or loose connections.
• **Repair or Replace: Repair any damaged wires or connectors as necessary.
• 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 primary module (often the PCM or another control module) is functioning correctly. This may involve checking for proper operation or testing the module with a scan tool.
• **Communication Test: Use a scan tool to check if the affected module is communicating with other modules on the network.
• Inspect the SCP Bus: **Bus Integrity: Check the integrity of the SCP bus wiring. Look for shorts, opens, or high resistance in the communication lines.
• **Signal Quality: Use an oscilloscope to check the signal quality on the SCP bus. Look for any irregularities in the waveform.
• Check for Interference: Ensure that there are no aftermarket devices or modifications that could be interfering with the SCP communication.
• Perform a Hard Reset: Disconnect the battery for a few minutes to reset the vehicle’s control modules. Reconnect and see if the code reappears.
• Update Software/Firmware: Check if there are any software updates available for the vehicle’s control modules. Sometimes, manufacturers release updates to fix communication issues.
• Consult Technical Service Bulletins (TSBs): Look for any TSBs related to the U1207 code for your specific vehicle make and model. Manufacturers may have specific recommendations or known fixes.
• Professional Diagnosis: If the issue persists after performing the above steps, consider seeking help from a professional mechanic or dealership. They may have specialized tools and knowledge to diagnose complex communication issues. By following these troubleshooting steps, you should be able to identify and resolve the underlying issue causing the U1207 code.