Toyota Motor Corp. said Monday that power output data had been manipulated for 10 of its models sold globally, in a new blow to the world's biggest automaker group, which has been plagued by a series of quality control issues in recent years.

Its affiliate Toyota Industries Corp. fabricated the data on diesel engines it makes and supplies for the automaker, Toyota said, adding that it will suspend shipment of the affected vehicles, including the Land Cruiser 300 and the Hilux.

"We sincerely apologize for causing tremendous trouble to our customers," Toyota President Koji Sato told reporters in Tokyo, adding the automaker will do all it can to resolve the problem as quickly as possible.

The revelation comes as a number of quality issues have been shaking the group's foundation.

Toyota Industries Corp. President Koichi Ito (front) bows in apology at a press conference in Tokyo on Jan. 29, 2024. (Kyodo)

Toyota's small-car unit Daihatsu Motor Co. stopped all shipments at home and abroad last month after a third-party investigation found that safety tests for most of its models were rigged.

Hino Motors Ltd., another Toyota subsidiary, admitted in March 2022 to submitting fraudulent emissions and fuel economy data to transport authorities.

The 10 models also include the Hiace, the Fortuner and the Innova. The cars were sold in Japan, Europe and the Middle East, among other markets. The output data rigging dates back to 2017, Toyota Industries said.

"We feel deeply responsible for the misconduct, which persisted for a long time, and for failing to discover and rectify it," Toyota Industries President Koichi Ito said at a press conference. "We will do our utmost to rebuild the company with legal compliance as our top priority."

Toyota has decided to stop six production lines at four of its domestic factories until Feb. 1 due to the shipment halt, it said.

Toyota Industries doctored the volume of fuel injection in engine output tests in a bid to make the engines' torque, or rotational force, appear better than it was, according to a report by a third-party panel.

The panel blamed the company's corporate culture, saying it lacked the will to actively increase compliance amid an environment where it felt secure in its position as a Toyota supplier.

"Its data compliance has grown lax," Hiroshi Inoue, the head of the panel, said at a separate press conference.

Toyota said it has confirmed the affected engines and that following a reevaluation after the discovery of the rigging, the vehicles now comply with engine output standards.

Japan's Ministry of Economy, Trade and Industry said the problem shakes the foundation of the automobile certification system, instructing Toyota Industries to find out the cause of the problem. The Ministry of Land, Infrastructure, Transport and Tourism also said it will launch an on-site inspection at the company's factory in Aichi Prefecture on Tuesday.

Monday's announcement followed a revelation in March last year when Toyota Industries admitted to falsifying emissions data for its forklift engines. The third-party panel has been investigating the issue.

On Monday, Toyota Industries said the data rigging was found in more of its forklift engines, and it has stopped shipment of all the affected products.

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