Japanese automotive components manufacturer Hitachi Atsemo said an investigation had found misconduct had taken place over testing and other processes within the company for the last 40 years, affecting a much wider range of plants and customers than previously disclosed.

The company was formed in 2021 following the merger between Hitachi Automotive Systems, Keihin, Showa and Nissin Kogyo, employing 90,000 people in 27 countries.

It is jointly owned by Honda Motor and Hitachi and is a major manufacturer of automotive powertrain and chassis systems and components, as well as autonomous driving and connected systems.

Nissan Motor is also a major customer.

Hitachi Atsemo acknowledged the results of an independent special investigation committee tasked with fact finding and said it had been conducting its own independent investigation into its internal procedures.

The company in a statement: “We deeply apologise for the inconvenience and concern caused to our customers and related parties due to our inappropriate conduct in the regular tests of brake components and suspension components.”

The company said it recognised its compliance culture and management supervision system were inadequate for the duration of the conduct.

“In response, we have decided to implement improvement measures throughout the organisation, including related education, review of processes, and investment in human resources and facilities, with the aim of preventing the recurrence of inappropriate actions, and to continuously improve these measures.”

The company added its own internal safety analysis showed “all products encompassed by the inappropriate conduct functioned properly within the required performance margins, with no evidence of reduced safety. We have disclosed all known issues to our customers and have not identified any safety concerns or legal violations.”

CEO Brice Koch said: “We have now taken all the relevant measures to improve, to increase the robustness of our system and our company,” adding he did not expect any impact on growth or costs.