At the end of 1978, the Bryansk Engineering Plant built an experimental TEM2U diesel locomotive (numbered 001), which, unlike the TEM2 diesel locomotives, had a modified hood and driver's cab, as well as a number of new devices (a new control panel, noise suppressor, improved thermal insulation, etc.) . The design of the diesel generator, spring suspension has been improved on the locomotive, electric water heating in the cooling system is provided. The coupling mass of the diesel locomotive was increased to 123.6 tons. The TEM2U diesel locomotives were designed for both 1524 and 1435 mm gauges (TEM2A series). Since 1984, the plant began serial production of TEM2U diesel locomotives (from number 8002).