Toyota Motor and four other Japanese automakers have admitted to the falsification of testing data or improper testing.

The infractions are many — including the submission of false data, rewriting of engine-control software, false entries in test reports, conducting tests under inappropriate conditions and improper modification of test vehicles in crash tests.

Investigations are ongoing at a number of companies. The exact nature of the possible infractions and their severity remains unclear, while vehicle performance and safety are likely unaffected.