U1238 — SCP (J1850) Invalid or Missing Data for Experimental #4

What it means

U1238 is an OBD-II diagnostic trouble code: SCP (J1850) Invalid or Missing Data for Experimental #4.

Typical fix

Confirm the code with an OBD-II scanner, then inspect the component or circuit named above. Consult a vehicle-specific service manual for the full diagnostic and repair procedure.