U1106 – SCP (J1850) Invalid or Missing Data for Legislated Diagnostics

The ODBII code U1106 SCP (J1850) Invalid or Missing Data for Legislated Diagnostics indicates that the vehicle’s onboard diagnostic system has detected a communication issue or missing data related to legislated diagnostic functions, often due to a fault in the communication network or a malfunctioning module.

The severity of ODBII code U1106 is moderate.

Common Causes For: U1105 SCP (J1850) Invalid or Missing Data for Chassis Status Request

• Faulty wiring or connectors in the SCP network.
• Malfunctioning or damaged control modules.
• Poor ground connections.
• Intermittent electrical issues.
• Corrupted data communication between modules.
• Software or firmware issues in the control modules.
• Faulty or disconnected sensors.

Common misdiagnosis for U1106 SCP (J1850) Invalid or Missing Data for Legislated Diagnostics

• Faulty OBDII connector
• Bad ground connections
• Malfunctioning PCM (Powertrain Control Module)
• Corrupted software or firmware in the PCM
• Wiring issues or shorts in the communication lines
• Faulty sensors or actuators
• Issues with the vehicle’s battery or charging system
• Intermittent communication faults
• Problems with the vehicle’s diagnostic system or tools
• Incorrectly performed diagnostic procedures

Common Troubleshooting Steps

When dealing with OBD-II code U1106, which indicates “SCP (J1850) Invalid or Missing Data for Legislated Diagnostics,” there are several common troubleshooting steps you can follow to diagnose and potentially resolve the issue. Here’s a structured approach:

• Check for Additional Codes: Use an OBD-II scanner to check for any other trouble codes that may be present. Addressing related codes can help in diagnosing the root cause.
• Inspect the Vehicle’s Wiring and Connectors: **Visual Inspection: Look for damaged, frayed, or corroded wiring and connectors related to the SCP (J1850) communication lines.
• **Connector Integrity: Ensure that all connectors are securely attached and free of dirt or corrosion.
• Test the SCP Communication Lines: Use a multimeter or an oscilloscope to check the voltage levels and signal integrity on the SCP communication lines. Ensure that the signals are within the expected range.
• Check for Ground Issues: Ensure that the ground connections for the modules involved in the SCP communication are secure and free of corrosion. Poor grounding can lead to communication issues.
• Inspect Modules for Functionality: Identify the modules that communicate over the SCP bus (e.g., PCM, BCM, etc.) and check their functionality. A malfunctioning module can cause communication errors.
• If possible, perform a module reset or reprogramming if the manufacturer provides such procedures.
• Look for Software Updates: Check if there are any software updates available for the vehicle’s modules. Sometimes, manufacturers release updates to fix known issues.
• Perform a Network Test: If you have access to a professional-grade scan tool, perform a network test to see if all modules are communicating properly. This can help identify if a specific module is causing the issue.
• Check for Intermittent Issues: If the code is intermittent, monitor the vehicle’s performance and check for conditions that may trigger the code, such as specific driving conditions or environmental factors.
• Clear the Code and Test Drive: After performing the above checks and repairs, clear the code and take the vehicle for a test drive to see if the code returns.
• Consult Technical Service Bulletins (TSBs): Look for any TSBs related to the U1106 code for your specific vehicle make and model. Manufacturers may have documented common fixes for this issue.1
• Seek Professional Help: If the issue persists after performing these steps, it may be necessary to consult a professional mechanic or technician who has experience with your vehicle’s specific systems. By following these troubleshooting steps, you can systematically identify and resolve the underlying issue causing the U1106 code.