Assuming it is "ДТХ" in Russian (Russian "H" is like Latin "N" while Russian "X" is somewhat like to Latin "H"), closest to space I can find is "детектор термохимический". The device is described here. It is a detector that measures the trace concentrations of fuel vapor and burnable gasses in the air. It may make some sense next to the RP-LOX rocket, but I do not see how it could be critical during re-entry.
"Датчик измерения силы тока на эффекте Холла" (a current sensor using Hall effect) may have a potential for meaning, but it is also not clear where and how it may be required during the landing. "Действие террористического характера" means the "terrorist action". Hopefully not.
Google Search gives no result, Jandex (Russian search) gives the mentioned sensor, Russian Wikipedia has no such article.
I think "ДТХ" is a fictional device that only exists in the imagination of the film makers. Getting something "almost wrong" during critical phase of flight adds the desired amount of tension to the plot.