Can a DCC engine run on an analogue layout?

Whether your DCC engine can run on an analogue layout depends on the decoder fitted to the engine.

If the decoder is "analogue compatible" and the relevant CV (function) is activated, then yes, the engine will work with an analogue controller.

If the decoder is not "analogue compatible", the engine will not move at all on an analogue setup. In that case, the only solution is to remove the decoder and replace it by a blanking plate. This, in effect, makes the engine analogue and it will not work on DCC.