 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.