Around the world, auto assembly lines are going quiet, workers are idle and dealership parking lots are looking bare.

A shortage of semiconductors, the tiny but critical chips used to calibrate cars’ fuel injection, run infotainment systems or provide the brains for cruise control, has upended automaking.

A General Motors plant in Kansas City closed in February for lack of chips, and still hasn’t reopened. Mercedes-Benz has begun to hoard its chips for expensive models and is temporarily shutting down factories that produce lower-priced C-Class sedans. Porsche warned dealers in the United States this month that customers might have to wait an extra 12 weeks to get their cars, because they lack a chip used to monitor tire pressure.

The French automaker Peugeot, part of the newly formed Stellantis automaking empire, has gone so far as to substitute old-fashioned analog speedometers for digital units in some models.

The disruption could not come at a worse time. Demand for cars has bounced back strongly from the pandemic slump, with consumers ready to spend money they saved over the past year, eager to avoid airplanes by taking road trips. The supply of semiconductors is depriving carmakers of a chance to make up sales they lost.

“We have already a robust demand situation being more held back by the semiconductor issue than anything else,” Ola Källenius, the chief executive of Daimler, said in an interview.

Some automakers, such as Renault, have begun to triage their chips, reserving them for more costly models that bring more profit. “We’re trying to find an intelligent way to prioritize cars with the higher margins,” Clotilde Delbos, Renault’s deputy chief executive, told analysts on Thursday.

Some buyers may be lucky enough to take home a new car, but it may lack options that use specialized chips. Porsche has told U.S. dealers that for several months it won’t be able to deliver high-end seats in the Macan S.U.V. that can be adjusted 18 different ways, a popular upgrade. The necessary chips are unavailable.

One big reason automakers can’t find enough chips is that semiconductor manufacturers have given priority to manufacturers of smartphones, video game consoles and other consumer electronics, which tend to be more lucrative customers.

Posted in: USA