The aircraft landed safely. Fifteen crew members and 237 passengers were on board. The plane returned to the gate and was taken out of service for maintenance.
The passengers, who were on Flight 289, will depart for Shanghai on another airplane at about 2:30 p.m. Sunday, the spokesperson said.
The aircraft left O'Hare at 10:50 a.m. and returned at 11:14 a.m.