Impersonation is a mean, which can often but does not always necessitate fraud.
One might impersonate Arnold Schwarzenegger for comedic effect, one might also impersonate a daughter to steal money from a grandma. Stealing the money is the crime here, one does not impersonate without purpose, the purpose defines the severity (or lack of) crime...
Impersonating someone else is always a serious crime. We call it fraud.