i have honda accord 2000 LX auto which has check engine light on and D4 light blinking and transmission making grinding noise. when it happened first time i went to honda dealer and he replaced sensor P 28900-P6H part . After a week i had the same problem, this time the dealer replaced the transmission since it was under warrenty. but week after having new transmission i have the same problem. i was wondering what is happening. i am not able to make anything out of it. it usually happens when it rains and road conditions are wet. any help will be greatly appreciated.

 

take it back to the dealer. If it only happens when it's wet out...it doesn't sound too good.

 

just take your car back to the dealership, you have warranty still, its a parts warranty item and they have to replace it again, if that is the problem, remember the trans they put on your car is rebuilt and not all of them are rebuilt correctly
good luck