Jessica Simpson's father is maintaining his innocence.
Maxwell's grandpa was pulled over by police on Ventura Boulevard in Sherman Oaks, Calif., not too far from the Simpson family homestead.
Should the case go the distance, a pretrial hearing has been set for Oct. 11 in Van Nuys Superior Court.
Simpson, 54, was not required to appear in person today as his is a misdemeanor case, so his lawyer entered the plea on his behalf.
If convicted on both counts, Simpson faces a maximum penalty of six months in jail, three years of probation and a $1,000 fine.