02 Regal harsh shift

[Datadave1]

I have a 2002 Regal LS 196000 miles and am getting a harsh shift with a P1811C code. 3.8 engine, MN3 code 4T65E and I was wondering if I should try the ZZ shift kit and the sea foam trick.

[maxwedge]

Assuming the trans is not slipping or just bad that is usually caused by a bad pwm solenoid, do a site or google search, plenty of info on that code.

[maxwedge]

Assuming the trans is not slipping or just bad that is usually caused by a bad pwm solenoid, do a site or google search, plenty of info on that code.

[Tech II]

The usual fix for P1811 is a PCS solenoid......have heard of the shift kit working too......shift kit is less labor intensive than the solenoid....

[Datadave1]

Took car for a drive last night, when the trans. temp gets warm (170+) the 1st to 2nd shift get long, .6 to 1.0/sec. and I was wondering if that would tell the PC sol.to jack up the pressure and set the P1811 code and give it the harsh shift or is it the PC sol.

[Tech II]

You have a transmission with a lot of miles on it....it could be the PCS....it could also be the clutch packs slipping with that kind of mileage...

I don't know the maintenance history of your tranny, or how you drive.....a road test with a scan tool looking at rpm slippage, while under a slight load might shed some light on the situation...if slippage is excessive, and full line pressure is commanded and slippage goes to zero, it's possible just a solenoid is the problem.....but this is an expensive job....you have to decide how far you want to go.....just replace that solenoid, or all of them and the valve body while you are in there.....but if your clutch packs are worn, this could all be for nothing.....and a transmission service should be done too(TOTAL FLUSH)....

A big factor, is the condition of the rest of the car and how long you want to keep it.....

[GTP Dad]

Unfortunately, I disagree with Tech II concerning the transmission flush. With a high mileage GM transmission a flush is a death sentence. You might as well save your money on the flush and just look for another transmission because if you flush it will die a rapid death shortly thereafter. I recommend a fluid and filter change but not a flush.

If you are planning on keeping the car a transmission rebuild may be a viable alternative. It will cost around $1200 but it may solve a bunch of issues. And given the fact that is is much cheaper than a new car payment it would be worth it. Of course if the car is in otherwise bad shape then go for another car!

[Datadave1]

I do plan on keeping this car for a while as it is still in good shape for a life here in Upper Michigan. I have ordered a ZZP shift kit and will install that and some Dex-VI and maybe start looking for another to have rebuilt as I also have an 03 Impala with the same problem @ 101,000 miles. Thank you everyone for your comments.