Car engine noise happens when the battery is full on 2008 Toyota Prius

Car engine noise happens when the battery is full, especially when going down the slopes and the battery charge full... coming down when i Stomps on the accelerator whats the problem ??

by in Clinton, IA on January 21, 2014
2 answers
ANSWER by on January 21, 2014
Nobody knows! A Toyota tech 'might' if he test drove it then ran a diagnostic test. Oh you'll probably get plenty of gusses! Hang in there!! Here you go!!
ANSWER by on January 21, 2014
Are you using "B" mode when going downhill?