U1217 – SCP (J1850) Invalid or Missing Data for External Lamp Outage

The ODBII code U1217 indicates that there is invalid or missing data related to an external lamp outage, typically involving communication issues between the vehicle’s modules regarding the status of external lights.

The severity of ODBII code U1217 is generally considered moderate.

Common Causes For: U1216 U1216: “Control Module Communication Loss”

• Faulty or damaged wiring/connectors
• Malfunctioning external lamp (e.g., brake light, turn signal)
• Failed body control module (BCM)
• Issues with the vehicle’s communication network
• Corroded or loose ground connections
• Faulty or missing bulbs
• Software glitches in the BCM or related modules
• Intermittent electrical connections

Common misdiagnosis for U1217 SCP (J1850) Invalid or Missing Data for External Lamp Outage

• Faulty Body Control Module (BCM)
• Defective Headlight or Taillight Bulbs
• Wiring Issues or Short Circuits
• Corroded Connectors
• Malfunctioning Light Switch
• Faulty Instrument Cluster
• Incorrectly Installed Aftermarket Lighting
• Software Glitches in the Vehicle’s Computer System

Common Troubleshooting Steps

When dealing with OBD-II code U1217, which indicates “SCP (J1850) Invalid or Missing Data for External Lamp Outage,” there are several common troubleshooting steps you can follow to diagnose and potentially resolve the issue. This code typically relates to communication problems within the vehicle’s network, particularly concerning the external lamp status. Here are the steps you can take:

• 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 U1217 code.
• Inspect the Wiring and Connectors: Examine the wiring and connectors related to the external lamps (headlights, taillights, turn signals, etc.) for any signs of damage, corrosion, or loose connections.
• Pay special attention to the wiring harnesses that connect to the Body Control Module (BCM) and the external lamps.
• Test the External Lamps: Verify that all external lamps are functioning correctly. Replace any burnt-out bulbs and ensure that the sockets are clean and free of corrosion.
• Check the Body Control Module (BCM): The BCM is responsible for monitoring and controlling the external lamps. Ensure that the BCM is functioning properly.
• If possible, perform a BCM reset or reprogramming if you suspect it may be malfunctioning.
• Inspect the SCP (J1850) Communication Network: Check the vehicle’s communication network for any faults. This includes inspecting the data lines for shorts, opens, or interference.
• Use a multimeter or oscilloscope to check for proper voltage levels and signal integrity on the SCP bus.
• Look for Ground Issues: Ensure that all ground connections related to the BCM and external lamps are secure and free of corrosion. Poor grounding can lead to communication issues.
• Perform a Visual Inspection: Conduct a thorough visual inspection of the vehicle’s electrical system, looking for any signs of tampering, aftermarket modifications, or other issues that could affect the electrical system.
• Clear the 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 U1217 code for your specific vehicle make and model. Manufacturers may have issued guidance or fixes for 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 your vehicle’s specific systems. By following these troubleshooting steps, you should be able to identify and resolve the underlying issue causing the U1217 code.