The fact that you are charged with a DUI, by itself, does not automatically make a person at fault for an accident.  However, it has historically been deemed a good indicator of who was at fault.  There does tend to be a heavy bias against persons who are charged with DUI and who are involved in an accident.  At trial, you would have the right to refut the evidence with any other available evidence.  For example, if an eye witness states that the other car clearly ran a stop sign and hit you, then the eye witness testimony and physical evidence would support a negation of liability.  Even with the bias, a plaintiff still has the responsibility of proving causation-- which means showing that an accident would not have happened "but for" your actions.