[1] Due to an economic crisis within Poland, it was impossible to start local production, so PKP decided to buy 200 locomotives produced in FAUR (former 23 August Works) from Bucharest, Romania.

The very first month of service revealed a series of failures that were reported back to the producer.

Locomotives were given new 12V396TC14 diesel engines with an electronic regulator produced by MTU, on-board diagnostics system, more convenient dashboards, fire extinguishing installation, and new lights.

Power from diesel engine to traction motors is delivered through electrical transmission.

During summer months all power from heating is transferred to traction motors, thus increasing tractive effort.

[1] Traction motors, bogies, transmissions, and compressor, as well as several different parts are similar to those used in ST43 locomotive.

The relatively low weight this locomotive puts on rails allows it to run on tracks laid on unstable surfaces.