In July 2015, Metro released a request for proposals seeking a contractor to pick-up and then dispose of all 1000-series and 4000-series cars, as part of its plan to replace those cars with the new 7000-series cars. On November 17, 2016, Metro discovered a glitch in which a 4000-series car would display an incorrect speed limit to a train operator while in manual mode. All 4000-series cars were taken out of service in the afternoon, but were returned to service in the middle of trainsets. Metro announced that they would discontinue using 4000-series railcars in lead positions and considered accelerating the retirement of the cars to late 2017 or possibly earlier.