What Does U1239 Mean?
Duplicate of U1238, indicating the same experimental #4 data communication issue on the SCP network. Multiple instances suggest widespread network problems or configuration errors affecting multiple modules.
Common Causes
35%
Multiple modules requesting unavailable experimental feature data
30%
Widespread SCP bus communication failure affecting multiple nodes
20%
Incorrect vehicle configuration programmed across multiple modules
10%
Corrupted data being broadcast on network causing rejection
5%
Software glitch in network message handling
Diagnostic Steps
1
Step 1: Compare this code with U1238 to determine if both are set by same module or different modules
2
Step 2: Use scan tool to identify all modules requesting experimental #4 data
3
Step 3: Check SCP bus integrity with oscilloscope to verify proper signal voltage and termination
4
Step 4: Verify vehicle build configuration matches module programming for all network nodes
5
Step 5: Reprogram all affected modules with latest software if configuration mismatch is confirmed
Estimated Repair Cost
$100 - $450
Parts + labor, varies by vehicle and location
Duplicate of U1238, indicating the same experimental #4 data communication issue on the SCP network. Multiple instances suggest widespread network problems or configuration errors affecting multiple modules.
The most common cause of U1239 (SCP (J1850) Invalid or Missing Data for Experimental #4) is: Multiple modules requesting unavailable experimental feature data
Typical repair costs for U1239 range from $100 to $450, depending on the vehicle, location, and whether you do it yourself or go to a shop.
No safety impact. This affects optional or experimental features only and does not compromise vehicle operation or safety systems.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to U1239 to identify the root cause.
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Quick Info
Category
Network
System
Body Control / Experimental Features
Difficulty
Type
Manufacturer
Recommended Tools
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