U1222 – SCP (J1850) Invalid or Missing Data for Interior Lamps

The ODBII code U1222 SCP (J1850) indicates that there is invalid or missing data related to the interior lamps, which may suggest a communication issue between the vehicle’s modules regarding the status of the interior lighting system.

The severity of ODBII code U1222 SCP (J1850) Invalid or Missing Data for Interior Lamps is generally considered moderate.

Common Causes For: U1221 U1221: “Control Module Communication Failure”

• Faulty interior lamp control module
• Damaged wiring or connectors
• Short circuit in the wiring harness
• Open circuit in the wiring harness
• Malfunctioning body control module (BCM)
• Corroded connectors
• Software issues or programming errors
• Faulty interior lamps or bulbs
• Issues with the vehicle’s communication network

Common misdiagnosis for U1222 SCP (J1850) Invalid or Missing Data for Interior Lamps

• Faulty interior lamp bulbs
• Defective body control module (BCM)
• Wiring issues or shorts in the interior lamp circuit
• Malfunctioning door switches
• Issues with the vehicle’s battery or charging system
• Faulty connectors or terminals
• Problems with the instrument cluster
• Software glitches or outdated firmware in the BCM

Common Troubleshooting Steps

When dealing with OBD-II code U1222, which indicates “Invalid or Missing Data for Interior Lamps” on a vehicle using the SCP (J1850) protocol, 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. Sometimes, multiple codes can provide more context for the issue.
• Inspect the Wiring and Connectors: **Visual Inspection: Look for any damaged, frayed, or corroded wiring and connectors related to the interior lamps and the body control module (BCM).
• **Connector Integrity: Ensure that all connectors are securely attached and free of corrosion.
• Test the Interior Lamps: **Functionality Check: Manually test the interior lamps to ensure they are functioning correctly. Replace any burnt-out bulbs.
• **Switch Operation: Check the operation of any switches that control the interior lamps (e.g., door switches, dimmer switches).
• Check the Body Control Module (BCM): **BCM Functionality: The BCM is responsible for controlling various electrical functions, including interior lamps. Ensure that the BCM is functioning properly.
• **Software Updates: Check if there are any software updates available for the BCM that may address known issues.
• Inspect the SCP (J1850) Communication: **Data Bus Integrity: Use a scan tool to monitor the data bus for any irregularities. Ensure that the SCP communication is functioning correctly.
• **Check for Short Circuits: Look for any short circuits or open circuits in the data lines that could affect communication.
• Perform a Hard Reset: Disconnect the vehicle’s battery for a few minutes to reset the BCM and clear any temporary glitches. Reconnect the battery and see if the code returns.
• Check for Ground Issues: Ensure that all ground connections related to the BCM and interior lamps are secure and free of corrosion.
• Consult Wiring Diagrams: Refer to the vehicle’s wiring diagrams to trace the circuits related to the interior lamps and the BCM. This can help identify any potential issues in the wiring.
• Professional Diagnosis: If the issue persists after performing the above steps, consider seeking help from a professional mechanic or automotive technician who has experience with your vehicle make and model.
• Document Findings: Keep a record of any findings, repairs made, and whether the code returns after clearing it. This information can be helpful for further diagnosis. By following these steps, you should be able to identify the root cause of the U1222 code and take appropriate action to resolve the issue.