The system failure which prompted a shutdown of Toyota’s domestic plants earlier this week was caused by a parts ordering system update, sources have told Reuters.
There were 14 plants affected, along with 28 vehicle assembly lines.
The automaker stopped production for a full day as investigations were made.
A cyberattack was considered ‘unlikely’, a Toyota spokesperson said previously.
Reuters estimates that the cost of the stoppage could be around $356 million of revenue.
Toyota has not given details of what went wrong, clarifying only that it was not a cyberattack.