A teenage boy accused of posing as an emergency worker and speeding in a fake ambulance across Melbourne hopes to become a police officer.

The 17-year-old faces 120 charges including 10 counts of dangerous conduct and 10 counts of dangerous driving and on Wednesday it was suggested he might plead not guilty.

The van the teenager allegedly converted Credit:Seven News

The youth, who cannot be named because of his age, faced a children's court in Melbourne seeking access to a diversion program, which would mean he would avoid a criminal conviction.

The magistrate shot down the application, citing the gravity of the allegations.