This Preliminary Information communication provides steps the technician will uses to diagnose and repair vehicles that have low oil pressure after an oil change with the engine Regular Production Option Code L20, L77, L94, L96, L99, L9H, LC8, LC9, LH9, LMF, LMG, LY6, or LZ1. Vehicle may have Service Engine Soon lamp with Diagnostic Trouble Code P0521 or Low Oil Pressure message on the instrument panel. Dealer will need to determine if bulletin 10-06-01-008 was completed. If the bulletin was performed inspect the left rocker cover. Dealer will insure the left rocker can hold water without leaking. If leaks are found apply room temperature vulcanization silicone to the rocker cover if possible or replace the left rocker cover.