It appeared that the issue was resolved after with a pit stop later in the race, but after running out of the points for a number of laps Leclerc pulled back into the pit lane to retire the car.
The 26-year-old was not competing for points before the retirement, partly down to the issue though Ferrari's lack of qualifying pace carried over to the race.
Charles Leclerc retired from the Canadian Grand PrixFerrari struggled for pace in Canada
What has happened to Ferrari in Canada?
After winning his home race in Monaco two weeks ago, it has been from one extreme to the other for Leclerc.
Ferrari lacked pace all weekend, and both drivers were knocked out in Q2 in qualifying.
Meanwhile, their rivals - Sergio Perez aside - took advantage to take large points hauls away from Canada.
Most pressingly for Leclerc, the momentum he had built in the drivers' championship over the past few races evaporated.