David Hasselhoff's daughter, Hayley, has been charged in her DUI case and we've learned her blood alcohol was off the charts. 

Law enforcement tells TMZ ... Hayley blew a .14 last month when cops found her passed out in her Mercedes on an L.A. freeway off-ramp. The legal limit in California is .08.

As we first reported ... she had to be taken to a hospital before she was booked.

Now, the city attorney has officially charged Hayley, and if convicted she faces up to 6 months in jail and a $1,000 fine.

That sentence is almost unheard of though for first, and even second-time offenders.