Forty-one-year-old Victor Kalinitchii, of Philadelphia, admitted that he was "grossly negligent" during Tuesday's appearance in Montgomery County Court.
Prosecutors say Kalinitchii and two other men were responsible for the death of 50-year-old David Schreffler in January when the truck's brakes failed, causing it to rear-end Schreffler's car.
The truck's other owner, who was driving at the time of the crash, and a mechanic have pleaded guilty to vehicular homicide and related charges.
State police say the truck bore an inspection sticker but was never inspected.
