Subaru has confirmed around 900 vehicles produced between December 2012 and November 2017 have had "certain measurements" like fuel economy and emissions data "inappropriately altered" following an internal investigation.
In December last year, the company was ordered by the Japanese Ministry of Land, Infrastructure, Transport and Tourism (MLIT) to conduct an investigation after it identified nonconforming final vehicle inspections at the company's Gunma and Yajima manufacturing facilities.
During interviews as part of the inquiry, some Subaru employees stated certain data "with respect to fuel economy emissions may have been altered" during final vehicle inspections.
The company reviewed measurement data from 6530 vehicles produced from "at least" December 2012 and November 2017, and found 903 units had their data inappropriately altered, though the misconduct could allegedly have been occurring as early as 2002.
"Data from prior to November 2012 was not found in measurement equipment or elsewhere, and it could not be checked based on specific data whether measurement values had been inappropriately altered in that period," Subaru said in a statement.
"Based on the employees’ statements, there is a high probability that such manipulation of fuel economy and emissions data commenced around 2002, however, this could not be confirmed."
The alterations were allegedly "decided" by factory floor inspectors and foremen, with manipulation methods passed from senior to junior inspectors in relevant workplaces.
While "no instructions were issued by, and no reports by foreman were made to" group chiefs, Subaru says some group chiefs "are considered to have been aware of the possibility of alterations".
The company argues the following categories could provide motivation for altering fuel and emissions data:
- "Subaru’s internal rules stipulate that, as a means of quality control for both fuel economy and emissions, average values for a certain number of vehicles or for a certain period of time, rather than results for each vehicle, must meet internal quality control standards. However, inspectors engaging in sampling of fuel economy and emissions were instructed by their seniors that, if results for each vehicle did not meet such standards, measurement values should be altered to those that meet such standards, and, according to such instructions, the inspectors altered measurement values.
- "Even if there were no problems in comparison with the internal quality control standards, inspectors altered measurement values with the intention of reducing variance in measurement values in order to avoid questions from the Group Chiefs and the Section Chief on such variance. It should be noted that alterations were made not only to make results better, but also to make them worse.
- "Although the relevant laws and regulations stipulate that, in certain limited cases, measurement values could be altered in order to adjust errors caused by measurement equipment, inspectors misunderstand such adjustment method because of deficient internal rules and inadequate training. Inspectors altered measurement values by adjustment methods not stipulated in the relevant laws and regulations, without understanding that their methods were inappropriate."
Subaru says it regards the conduct as "inappropriate" and "an extremely serious compliance problem". However, the company adds that because its internal quality control standards are stricter than that stipulated by Japan's Safety Standards, there are no data alterations that would "require recalls or present other quality issues".
"We would like to reiterate our deepest apologies for the significant trouble and inconvenience caused to our customers, partners, and all other stakeholders," the company said.