A teenager stalled a Renault Clio at a static police checkpoint at Main Road in Glynn and police then discovered he was under the influence of cannabis.
A strong smell of the drug was detected from the vehicle being driven by Adam Collim (18), of Craiganboy Park, Glynn, in October last year and a small bag of cannabis was found during a search.
The defendant told police he had smoked cannabis a couple of hours before driving.
The defendant admitted a charge of driving whilst unfit.
Defence solicitor Kevin MacAllister said his client stalled the car at a police checkpoint.
The court heard the matter had been previously adjourned to allow the defendant to complete his A Levels.
The defendant was banned from driving for a year and fined £150.