Toyota Motor's Daihatsu unit will halt shipments of all vehicles both overseas and in Japan, it said on Wednesday, after an investigation into a safety scandal found issues at some 64 models, including 22 sold under the Toyota brand.
An independent panel has been investigating Daihatsu after it said in April it had rigged side-collision safety tests carried out for 88000 small cars, most of which were sold under the Toyota brand.
The latest revelations suggest that the scope of the scandal is now far greater than previously thought and could potentially tarnish the automakers' reputation for quality and safety.
Toyota said in a statement "fundamental reform" was needed to revitalise Daihatsu as a company in addition to a review of certification operations.
"This will be an extremely significant task that cannot be accomplished overnight," it said. "It will require not only a review of management and business operations but also a review of the organisation and structure."
The automaker, which makes small cars, was found to have cheated on safety tests of almost all models it currently has in production as well as some cars it made in the past, the Asahi newspaper previously reported.
Daihatsu said in April it had discovered the wrongly conducted tests after a whistleblower report. It also said it had reported the issue to regulatory agencies and halted shipment of affected models.
The following month, Daihatsu said it had stopped sales of the Toyota Raize hybrid electric vehicle and its own Rocky model after also finding problems with testing for those two models.
Daihatsu produced 1.1 million vehicles over the first 10 months of the year, nearly 40% of those at overseas sites, according to Toyota data. It sold some 660 000 vehicles worldwide over that period and accounted for 7% of Toyota's sales