The shutdown at the Windsor Assembly Plant will last at least another two weeks.
Unifor Local 444 informed its members the plant will not be operating the weeks of July 19 and July 26.
Stallantis has been facing a microchip shortage since the end of March. The plant has only opened periodically since that time.
Officials say the operation of the plant will only be known on a week-to-week basis based on parts supply.
The microchip shortage has also affected a Stellantis SUV plant in Detroit, which will be shut down through August 1, according to Crain's Automotive News.
The annual summer shutdown is still scheduled for the week of August 16.