Japan's transport ministry inspected Yamaha Motor Co.'s headquarters in Shizuoka Prefecture on Wednesday, a day after probing Toyota Motor Corp., over improper vehicle certification tests engulfing the auto and motorcycle sectors.
Yamaha said earlier this week that it had conducted noise tests for its motorcycles under improper conditions and reported falsified data in another test, leading the ministry to order a halt of shipments of its YZF-R1 motorcycles.
Four other companies -- Toyota, Honda Motor Co., Mazda Motor Corp. and Suzuki Motor Corp. -- have admitted to similar misconduct, significantly undermining the reputation of Japanese cars and motorcycles.
The Ministry of Land, Infrastructure, Transport and Tourism said it will decide whether recalls are required after examining whether the companies' vehicles meet its standards for safety and environmental performance.
The ministry plans to investigate the three other companies soon.
The latest misconduct was discovered after the transport ministry instructed 85 automakers and parts suppliers to investigate whether certifications were acquired properly following a series of similar scandals that hit Toyota group firms in 2022 and later.
