Osunaarashi, Japan’s first wrestler from Africa, caused the accident in January, despite sumo wrestlers being banned from driving by the sumo association, media reported.
The 26-year-old, whose real name is Abdelrahman Shalan, had initially told the Japan Sumo Association his wife was driving but later admitted to police he was the driver.
He will accept the punishment, the second most severe after dismissal.
The sumo association could not immediately be reached for comment.
The scandal is the latest in a string of humiliations for the traditional Japanese sport.
In January, the sumo association was forced to take disciplinary action against a top-ranked referee who sexually molested a teenage colleague.
After a bout of drinking, 58-year-old Shikimori Inosuke kissed his junior colleague and touched his chest at a hotel in Okinawa, where sumo wrestlers were on a winter tour.
The top referee, whose real name is Itsuo Nouchi, apologised for his behaviour and later submitted a resignation letter to the association.
Sumo is still recovering from a damaging scandal last year when former sumo grand champion Harumafuji was charged over a brutal assault on a rival wrestler while out drinking.
The Mongolian former “yokozuna”, sumo’s highest rank, faced a summary indictment meaning he was fined 500,000 yen ($4,420) but was exempted from standing trial.
