(Bloomberg) -- Toyota Motor Corp.’s group sales lost momentum in January after government probes revealed decades of fraud at two major affiliates.

Worldwide sales, including those of subsidiaries Daihatsu Motor Co. and Hino Motors Ltd., rose 4.4% to 831,161 units last month compared to January 2023, the Japanese automaker said Wednesday. Production fell 3.8% to 788,670 units, the first global decline in 13 months.

Toyota and its luxury brand Lexus saw sales and output grow in January while its truck-making subsidiary, Daihatsu — still recovering from a safety certification scandal that erupted in December — witnessed global sales and production plummet 51% and 68% respectively.

Toyota just came down from a bumper year, however, having sold more passenger vehicles than ever after demand for hybrids and recovering supply chains helped it maintain its lead over Volkswagen AG as the world’s top carmaker for a fourth year running.

But in late December, an internal investigation revealed that Daihatsu, which sells and supplies lightweight “kei” trucks, had been been manipulating crash safety test results dating as far back as 1989. Daihatsu has been a wholly owned subsidiary of Toyota since 2016.

Then in January, Toyota Industries Ltd. was found to have altered power output data for several engines it was supplying to Japanese carmakers. 

Read more: Toyota Chairman Calls on Entire Group to ‘Return to Basics’ 

The Japanese transport ministry revoked certification for and suspended domestic manufacturing of a number of the vehicle models and engine types, though most factories have restarted or announced a restart date.

On Wednesday, Toyota said it will resume production on March 4 at plants in Mie and Gifu prefectures after the transport ministry lifted bans on three engine types made by Toyota Industries. Daihatsu announced the same day it will resume production on March 18 of three vehicles, including the Rocky, Toyota Raize and Subaru Rex.

Nissan Motor Co.’s global production rose 22% to 274,462 units in January, it said Wednesday, while sales were up almost 17% to 266,895.

Honda Motor Co. saw output rise 20% to 337,119 units last month as domestic sales grew 18% to 53,402.

(Updates with Daihatsu statement and monthly figures from Nissan, Honda in final paragraphs.)

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