The launch customer is the Massachusetts Bay Transportation Authority (MBTA), whose first unit entered revenue service in April 2014.

[3][5] In the mid-2000s the MBTA issued a request for proposal for new diesel locomotives to replace its aging fleet, much of which dated to the late 1970s.

[12] En route to the MBTA, the locomotives were sent to the Providence & Worcester Railroad, which is subcontracted to MPI to prepare the units for revenue service.

[12] In August 2014, MPI discovered that some traction motor bearings had been shipped improperly to their factory, causing early failures.

[13] While the repairs were performed under warranty at no cost to the MBTA, they constituted an additional delay that prevented some of the units from entering service before the end of 2015.

The multiple delays and early mechanical issues have raised concern from industry commentators about the MBTA's procurement process and the overall quality of the locomotives.