Toyota Halts Shipments of 10 Models Over Mishandling of Engine Tests

Toyota said it has halted the global shipments of 10 vehicles after it discovered that an affiliate had mishandled the testing of diesel engines used in the automobiles, the latest embarrassing problem to hit the world’s biggest automaker in recent months.

A Toyota affiliate used software to measure horse power output that made “values appear smoother with less variation,” Toyota, the parent company, said in a statement. The vehicles “meet engine output standards,” and there is no need to stop using the engines or vehicles, the company said.

Still, Toyota decided to stop shipping the 10 models that use three diesel engines at issue. Among the models that will temporarily be shut down is the popular Hilux pickup truck and the Land Cruiser 300 SUV. Toyota did not say how many vehicles were affected.

In December, Toyota was rocked by a series of recalls and production shutdowns. First, it recalled about 1 million vehicles in the United States because of an issue with airbags. Then, it reported that Japan’s government was investigating Daihatsu, the subsidiary, for safety problems that dated back decades.

Daihatsu said it would stop shipments of all of its models because of the safety-inspection irregularities. Last week, it said it was recalling 320,000 Daihatsu vehicles and was still not ready to reopen its production facilities.

Toyota said it understood “the gravity” of the two back-to-back testing problems that “have shaken the very foundations of the company as an automobile manufacturer.”

Japanese auto companies are facing their biggest business challenge since becoming global giants in the 1980s. Toyota, which in the 1970s became the leader in automotive manufacturing efficiency, has failed to keep up with changing consumer preferences and a push by governments around the world to greatly reduce the burning of fossil fuels, the main cause of climate change. Last year China supplanted Japan as the world’s largest exporter of cars.