The orbiter put itself into the protective standby mode early Friday when it detected unusual readings from one of its three reaction wheels, which are used to control its orientation, SPACE.com reported.
"The spacecraft is safe, and information we've received from it indicates the problem is limited to a single reaction wheel," mission manager Chris Potts of NASA's Jet Propulsion Laboratory in Pasadena, Calif., said in a statement. "The path forward is evaluating the health of the reaction wheel and our options for proceeding."
The orbiter is equipped with a spare reaction wheel onboard should one of the three primary wheels fail, NASA said.
Mars Odyssey has been studying the Red Planet since it arrived in orbit in 2011.
It has also served as a communications relay station for NASA's Spirit and Opportunity landers on the martian surface and will do the same for the next Mars rover, Curiosity, when it lands in August.