i have a 2005 monte carlo with code p1811

Question

the monte has one code p1811 which does not trip my cel on the dash. it some times has slips out of gear for 2-5 seconds and catches hard, it does not slip back into gear. it seams to be 1st-2nd and 2nd- 3rd. what might be the cause, and how can i repair it before it damages the transmitain.

Answer 1

Start by checking/replacing the transmission fluid if it has not been serviced in the last 30k miles, if you still have the problem a you should take it to a  transmission specialist 

if there is hard shifting and there is metal in the transmission, the transmission might be bad.