While the war with Germany had already ended in May 1945, the prototypes were for the time being further tested by the UZTM design bureau during summer and autumn 1945. Several problems emerged, among them was the heating up of the vehicle's interior due to insufficient engine cooling. This was especially severe in the case of the driver, who was seated next to the engine and whose working station heated up to unbearable temperatures in summer. Another problem emerging was the very crammed and uncomfortable crew compartment. Finally, the SU-102 prototype faced structural problems, being not entirely suitable for absorbing the recoil of the powerful 122 mm gun. Yet these issues were deemed solvable and the vehicles were recommended for mass production after application of several modifications to address the prototypes' problems. Eventually, however, the end of World War II finally led to the conclusion that the vehicles had by now become unnecessary, and in the end, the production of the SU-101 and SU-102 was terminated before it began.