DETROIT — Stellantis is idling assembly plants that build the Ram 1500 Classic and Chrysler Pacifica minivan for at least three weeks because of the microchip shortage plaguing the auto industry.

Warren Truck Assembly just north of Detroit is scheduled to be down from Monday through April 18, according to an employee bulletin confirmed by the automaker. The plant, which has 3,405 workers on two shifts, is slated to start producing the Jeep Wagoneer and Grand Wagoneer SUVs in the second quarter.

“Stellantis continues to work closely with our suppliers to mitigate the manufacturing impacts caused by the various supply chain issues facing our industry,” the company said in a statement. “Due to the unprecedented global microchip shortage, production at the Warren Truck Assembly Plant will be down beginning next week through mid April.”

The automaker also is halting production of the Pacifica and Chrysler Voyager in Windsor, Ont., for four weeks starting Monday, according to Unifor Local 444.

Stellantis CEO Carlos Tavares said earlier this month that the company is looking to counter the shortage.

He said Stellantis is working “as fast as we can while respecting quality standards on finding alternatives for the semiconductors that are in short supply.”

AutoForecast Solutions said the Windsor shutdown will cost the plant about 14,000 units of production. That’s on top of an estimated 15,000 vehicles that weren’t produced during a three-week shutdown in March.

A global shortage of microchips has been crippling the auto industry.

General Motors Canada confirmed on Wednesday its CAMI plant in Ingersoll, Ont., will remain idled until at least mid-April. The Chevrolet Equinox is assembled there.

Ford’s Oakville, Ont., plant is partially assembling Ford Edge vehicles and storing them on lots until the required microchips arrive to finish them.

The Windsor Star reported Friday that Ford’s Essex Engine Plant in Windsor, Ont., will be down April 16.

But Unifor Local 200 president John D’Agnolo told the paper the microchip shortage will likely lead to more shutdowns in the future. The plant makes engines for the F-Series pickup, Mustang and E-Series commercial vans, and Ford on Friday idled production of the F-150 for three days at a plant in Michigan.

Meanwhile, Honda Canada would only say that its Alliston, Ont., factory, which builds the Civic, has been affected.

“In addition to the production suspension during the week of March 22, in which most of our mass-production auto plants in North America are impacted, some of the plants will also temporarily suspend production during the week of March 29,” Honda spokesman John Bordignon said in an email. “Since this is a fluid situation that requires flexibility; the details, timing and length of production adjustments could change.

The global chip shortage hit as auto plants ramped production back up after shuttering for two months during the COVID pandemic last year, creating a surging demand for makers of semiconductors who also must fill orders for consumer electronics. That has left carmakers competing for chips.

Semiconductors are used extensively in light vehicles: to monitor engine performance, manage steering or automatic windows and in sensors used in parking and entertainment systems.

Reuters contributed to this report.