An investigative committee found irregularities during horsepower-output testing that took measurements based on computer modules running software that ultimately differed from the software that was used for mass production, the Japanese carmaker said in a statement Monday. That resulted in values with less variation, it said.

The certification issue is the latest blow to beset Toyota, following an announcement by subsidiary Daihatsu Motor Co. last month that most of its vehicles weren’t properly tested for collision safety and that the automaker manipulated the results of tests dating as far back as 1989. As a result, Daihatsu is halting shipments and suspending operations through at least February.

“To move forward as a group it’s necessary to have a management system that values the voice of workers on ground,” Toyota Chief Executive Officer Koji Sato said, admitting that data fabrication is an issue at the automaker’s subsidiaries and there are communications problems.

Toyota will halt the production of the affected models in Japan immediately and stop the manufacture of impacted overseas models from Tuesday, Sato said, with production to restart on a country-specific basis.

“As the auto industry goes through a once-in-100-years change, we need to think how to deal with new challenges and technology,” he said.

Such misconduct cases “could damage Toyota Industries and, by extension, the Toyota group as a whole,” Bloomberg Intelligence Senior Analyst Tatsuo Yoshida said.

The committee involved in the Toyota Industries issue found irregularities during horsepower-output testing for three engine models. In total, 10 car models use the engines around the world, according to the company. Those include the Land Cruiser Prado, the Land Cruiser 300, the Fortuner and the Hilux.

The committee had initially been investigating Toyota Industries over certification related to engines used in forklifts. The latest findings came after the probe expanded to construction machinery engines and then diesel engines for cars.

Irregularities occurred “to avoid a delay in mass production,” Hiroshi Inoue, chair of the Special Investigation Committee, said at a separate briefing Monday, adding that “responsibility lies with higher management.”

Toyota Industries President Koichi Ito said “we weren’t communicating enough with Toyota Motor regarding the test process” after orders increased from 2017. He said he’ll seek to rebuild communications with the parent company. The impact of the scandal on earnings is currently unknown, Ito added.

Japan’s transport ministry will start on-site inspections on Tuesday.

“Going forward, we will be involved in all company-wide activities to help rebuild Toyota Industries and review the situation to thoroughly ensure that safety and quality are the top priorities,” Toyota said in a statement.

With the scandals at Toyota just piling up — Japanese truck maker Hino Motors Ltd., another Toyota unit, said in August that it found emissions data was falsified on its vehicles — Sato reflected that the common issue is around understanding and respect with regard to certification.