2002 Impala w/120,000 Code p1811

I have been reading the threads associated with P1811 about hard shifting. I am not having that problem. Just recently, when my car is warmed up, I occasionally get a severe hesitation on acceleration or just cruising. It feels like about a half second shut down and then it just returns to normal. It can happen two or three times in about 10 seconds and then not do it at all. I did notice that there is an RPM drop of about 500 RPM when it happens. It feels like the engine is quitting and recovering in that half second. The dealer came up with code P1811 and suggested a new transmission. If the tranny is slipping wouldn't I get an RPM spike? At all times the car shifts normal and the hesitation is within a gear range and not at a shift point. Also, since I have been getting the hesitation the check engine light might come on and stay on for a few starts and then just go away. Any suggestions???

Welcome to AF. 1811 is usually caused by a bad pressure control solenoid in the trans, I would get a second opinion on this, yes the trans can be slipping, less likely though.

did the CEL come on ? I would take the car to get a second opinion. I had to get a new trans, my trans was throwing that code too...my CEL was coming on. The car computer has an "abuse mode" progammed into like if you rev high and shove the gear seletor into a gear the engine is supposed to die...maybe that is why you are not seeing the high revs. Have you tried manually shifting the car from gear to gear to see what it will do, sarting in first and working your way to third.

I have been reading the threads associated with P1811 about hard shifting. I am not having that problem. Just recently, when my car is warmed up, I occasionally get a severe hesitation on acceleration or just cruising. It feels like about a half second shut down and then it just returns to normal. It can happen two or three times in about 10 seconds and then not do it at all. I did notice that there is an RPM drop of about 500 RPM when it happens. It feels like the engine is quitting and recovering in that half second. The dealer came up with code P1811 and suggested a new transmission. If the tranny is slipping wouldn't I get an RPM spike? At all times the car shifts normal and the hesitation is within a gear range and not at a shift point. Also, since I have been getting the hesitation the check engine light might come on and stay on for a few starts and then just go away. Any suggestions???

I would get another dtc reading appears with your discription like the engine has a miss fire...fuel pressures and fuel contamination[water]..

My 2002 Impala has 110,000 miles and a code of 1811. After driving for a while it shifts harder than normal (doesn't spill my coffee) during the first 2 gears. Unfortunatly, I was told you have to drop the transmission to get at the part. Estimate cost at a transmission shop was $1100.

The trans does not come out, the side cover must come off, yes it may have to be lowered some, get another estimate this is way too high.

Faulty Pressure Control Solenoid, GM knows about it, there are TSB about it. Harsh shifts when hot. The best and cheapest thing to do is call GM and complain. Their number is 1-800-222-1020. These transmissions are known to be defective but have yet to be recalled. I called today 6-21-2010. Ask for it to be recalled. If they get enough calls they will. Maybe

Here is the persons # i have been dealing with 1-866-790-5600 ext 11310. Tell her your problem, she wants to hear all about it. Tell her Danny with the 04 Impala told you to call. She will take care of it.

installed transgo sk4t65e kit and it works good now, try this first, GM was useless to talk to, but fun to bitch at