- Nope, there is no widespread use of a universal translator in the 40k universe
- A specific faction or organization may use one
- The knowledge machines could be thought of as a universal translator, to a fashion...
There is no general universal translator in the 40k universe. While it is possible that one faction or organization may have and use one, there is no widespread (as I assume you are referring to something that exists for all the races similar to Star Trek) use of a translator. If that exists I do not know of it.
The most obvious counter-example of this that I know of is the Space Wolves. The Space Wolves chapter, in addition to knowing High Gothic and Low Gothic (thanks to the knowledge machines), speak their own language that is native to their home planet Fenris. There are two dialects. The first is Wurgen or battle-cant that is spoken during combat and Juvjk or hearth-cant which is spoken outside of battle. These languages that the Space Wolves speak are really known only to themselves allowing them to speak in their native tongue around foreigners when they wish to speak privately. If there was a translator this would defeat the purpose.
And as I mentioned above there are knowledge machines that impart the extensive databases of knowledge into the new Space Marines so that they know what an Ork is, how to speak those other Imperium languages, weapon and armor maintenance, all of the indoctrination chants, etc. These can (such as the Space Wolves) teach the individual High and Low Gothic. We do not know everything that these impart, but it is possible they teach more languages.
As an example of other races, when humanity has interactions with the Eldar the work mon-keigh is thrown around almost all the time. I believe this is a kind of slang word for "inferior species" that the Eldar use given that they have been around since before humanity existed. In every instance the sentence has "english" and then mon-keigh thrown in for good measure. (i.e. "If you do not get out of our territory we will destroy you, mon-keigh")
And as far as I know no one knows anything about the language of the Necrons
(I was also going to mention astropaths as a kind of universal translator, but thinking about that it is not true at all. If anything I think they are the opposite. They probably have more in common with the Navajo code talkers than any universal translator.)
Edit: Just in case you wish to change the correct answer...