(过错 弱点) faultA bad point, but not of a serious moral kind. It refers to behavior and character. His only fault is that he lacks ambition.
find fault with sb / at fault shortcomingWeakness, failing
It refers to failures or deficiencies in things as well as people.
In spite of all her shortcomings I still think she's one of the best teachers in the school.
(疏忽) errorA mistake (formal sometimes literary)
It implies deviation from a standard or model
The accident was caused by human error.
(缺点 毛病) defectsth lacking or imperfect.
It refers to quality.
The radio was returned because of a defect.
看看上面的解释应该更清楚。。。