The driver was pulled over shortly before 5 p.m. in the 1300 block of Garnet Avenue near Fanuel Street, according to San Diego police Officer Dino Delimitros. It was unclear what prompted the traffic stop.
Firefighters and the Metro Arson Strike Team was also dispatched to investigate, a fire dispatcher said.
A nearby Starbucks was evacuated as a precaution.
Delimitros said traffic was being directed around the stopped vehicle.