U1155 – SCP (J1850) Invalid or Missing Data for Compact Disc

The ODBII code U1155 indicates that there is invalid or missing data related to the Compact Disc (CD) player, specifically in the context of the SCP (J1850) communication protocol.

The severity of ODBII code U1155 SCP (J1850) Invalid or Missing Data for Compact Disc is generally considered low.

Common Causes For: U1154 U1154: “Instrument Cluster Communication Loss”

• Faulty or damaged wiring/connectors
• Malfunctioning compact disc player
• Poor ground connection
• Issues with the vehicle’s communication network
• Software or firmware glitches
• Corrupted data signals
• Faulty control module
• Interference from aftermarket devices

Common misdiagnosis for U1155 SCP (J1850) Invalid or Missing Data for Compact Disc

• Faulty CD player
• Wiring issues
• Faulty audio system
• Software glitches
• Faulty communication module
• Corrupted data in the vehicle’s computer
• Incorrectly installed aftermarket audio equipment

Common Troubleshooting Steps

The OBD-II code U1155 indicates an issue with the communication on the SCP (Serial Communication Protocol) bus, specifically related to the Compact Disc (CD) player. This code typically means that the vehicle’s computer is not receiving valid data from the CD player or that the CD player is not communicating properly with the rest of the vehicle’s systems. Here are some common troubleshooting steps to diagnose and potentially resolve the issue:

• Check for Additional Codes: Use an OBD-II scanner to check for any other trouble codes that may be present. Other codes can provide additional context for the problem.
• Inspect Wiring and Connectors: Visually inspect the wiring and connectors related to the CD player and the SCP bus. Look for signs of damage, corrosion, or loose connections.
• Ensure that all connectors are securely plugged in and that there are no bent pins.
• Test the CD Player: If possible, test the CD player in another vehicle to see if it functions correctly. If it does not work in another vehicle, the CD player may be faulty and need replacement.
• Check the SCP Bus: Use a multimeter or an oscilloscope to check the SCP bus for proper voltage and signal integrity. Look for any interruptions or shorts in the communication lines.
• Ensure that the SCP bus is not being interfered with by other devices or components.
• Inspect the Vehicle’s Grounding: Ensure that the vehicle’s grounding points are clean and secure. Poor grounding can lead to communication issues.
• Reset the System: Disconnect the vehicle’s battery for a few minutes to reset the system. Reconnect the battery and see if the code reappears.
• Update or Reprogram Modules: In some cases, the vehicle’s software may need to be updated or reprogrammed. Check with the manufacturer for any available updates.
• Check for Environmental Factors: Ensure that there are no environmental factors affecting the CD player, such as moisture or extreme temperatures.
• Consult Technical Service Bulletins (TSBs): Check for any TSBs related to the specific make and model of the vehicle. Manufacturers may have issued guidance on common issues related to the U1155 code.
• 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 automotive electronics and communication systems. By following these troubleshooting steps, you can systematically identify and address the underlying cause of the U1155 code.