etc

We say "A, B, C, etc." but can we also say "A, etc"? Is it OK to use "etc" when there is only one example?

For example,
The system needs to process a various information (sensor info, etc).

Thank you.

"The system needs to process a various information (sensor info, etc)."

If you change "a various" to just "various", the sentence will be correct. Since "various information" implies plurality, you cannot use "a".

I don't think you could get away with "A, etc." but if you expect the listener/reader to have a good idea of what you mean using "etc." after only on item would be fine.