This Preliminary Information communication provides information to the technician for a Service Engine Soon light with a Diagnostic Trouble code P0300 set. There may be a rough running engine associated with this concern. If service information diagnostics have been completed and there is still no trouble found, the technician is to inspect for a possible terminal tension concern on the ignition coil power feed for the cause of the rough running engine and or the P0300. Â For the Service Engine Soon light or traction control lamp concern check the X2 connector of the under hood fuse block for poor pin retention.Â