2001 Chevrolet Monte Carlo SS. Engine size 3.8 codes = P1811.
I Changed transmission fluid and filter after noticing it having a burnt smell.
Just checked for trouble code
Question = After the above, I noticed car was taking too long to shift from 1st to 2nd gear and when it did you could feel the change harder than ever before. This does not happen every day I drive the car. I haven't been able to pinpoint any specific time this happens, it just randomly happens. It may act like this two days in a row and then not do it again for a couple of days. When scanned the code read P1811, so the technician cleared the code and told me to drive it and see if the problem still occurred and if so to return and he would scan it again to see if the same code came up. Does this mean I may need a whole new transmission or just maybe a solenoid or some other part? I am very concerned about the cost? Thank You.
2001 Monte Carlo Transmission Code P1811
Several things can cause this code. Most common is you have a faulty Pressure Control Solenoid.
May have a component in the transmission is slipping; just as the code states- 'p1811 transmission Component slipping' But normally the shifting problems would occur at all times. The harshness is happening because when the code appears, the trans will raise line pressure and change shift adapts to try and compensate for a slipping component.
A bad PCM, although not as common can also do this. Transmission needs to be checked by a qualified trans. Tech in order to get the problem isolated and not guess at the problem, because it could be very costly.