Silverado Secret

This bulletin applies to 2014-2018 Chevy Silverado vehicles equipped with a 4.3L, 5.3L or 6.2L engine. The customer may comment on an SES light on. The technician may find DTC P0300 set and/or a rough running engine concern.

If diagnostics have been completed with no trouble found, inspect for a possible terminal tension concern on both the ignition coil power feed for a possible cause of the DTC and/or a rough running engine, and the X2 connector of the UBEC (underhood fuse block) for an intermittent SES traction control lamp concern.