Japanese commercial vehicle and engine manufacturer Hino Motors, Ltd. has established a Special Investigations Committee to examine “Misconduct concerning Engine Certification” in the emissions and fuel economy performance of three Hino engines for the Japanese market.

Hino confirmed the misconduct regarding falsification of emissions, fuel economy performance, and engine performance of medium-duty engine model A05C (HC-SCR) and heavy-duty engine models, A09C and E13C.

The company also revealed fuel efficiency performance data for light-duty engine model N04C (Urea-SCR) was less than the specification values, while noting no misconduct has been alleged in this case.

The Special Investigation Committee will be composed of outside experts, “who have no vested interest in relation to Hino, to develop a clearer picture of the entire case and analyze the root cause,” according to a company statement. Officials expressed “deep” apologies for the “huge inconvenience” to customers and stakeholders and promised to take prompt measures upon the committee’s report.

The special committee will be chaired by Kazou Sakakibara, former superintending prosecutor, Osaka High Public Prosecutors Office.

The investigation has impacted at least one other Japanese firm. Toyota Motor Corporation issued a notice regarding the fuel efficiency performance to customers of its Coaster and Coaster Big Van models, which feature Hino’s N04C compact engine (with a urea selective catalytic reduction system). The models “actual fuel efficiency did not meet the values specified,” said Toyota, while noting the engine performance issue “has no impact on driving functionality and does not pose any safety concerns” for the Coaster models.