Randy Albert Gaster, 53, also admitted a misdemeanor count of driving on a suspended license causing injury and was immediately sentenced to 270 days in jail.
Once he completes the jail term, Gaster will be released to Sonoma County to face felony check fraud charges, said Superior Court Judge Kelly Mok.
San Diego police said Gaster ran a stop sign at the intersection of Pearl Street and Olivetas Avenue and lost control on a curve in the roadway shortly before 12:30 a.m.
His sedan crashed into a residential structure at the White Sands La Jolla assisted-living center, winding up partially inside the building and fatally injuring Robert Gault.
Toxicology results showed Gaster was not impaired at the time of the crash, according to the City Attorney's Office.