OBD-II FAULT CODE
U1238

SCP (J1850) Invalid or Missing Data for Experimental #4

Reference information for U1238. Because this is manufacturer-specific, confirm the exact definition for the vehicle before using the diagnostic guidance below.

Manufacturer-specific code

This code can have different meanings depending on vehicle make, model and year. Treat the definition below as a reference and confirm it with OEM service information before diagnosis or repair.

NetworkSystem
Network / communicationCategory
HighSeverity
  • Multiple warning lights or modules not communicating
  • Low battery voltage
  • Blown module fuse
  • Poor ground
  • Open/short on communication bus
  • Module offline
  • Check battery condition, module fuses, grounds and network connectors before replacing modules
  • Run a full system scan to identify modules not responding
  • Inspect CAN/SCP wiring, connectors and grounds
  • Repair power/ground or network wiring fault first
  • Only consider module replacement after wiring and power supply checks pass
Need more help?

Search manuals, wiring diagrams and technical service bulletins.

Not sure what to do next?
Get step-by-step instructions and professional repair information.
Disclaimer: Information is provided for general guidance only and may not apply to all vehicles. Always consult a qualified technician.