98 lesabre info on pressure control solenoid PSC

[papason]

98 Lesabre 66,000 Miles. Took car to dealer to get this reset. They said it needs to be replaced. I was told by someone who had the same problem and they got it reprogramed. I have not seen this mentioned here. Is anyone familiar with them being reprogramed?
I get the studder sometimes on take-off.

Also if it needs replaced is it hard to do it yourself? where is it and what does it look like? of course also HOW? Is this similar to the clutch control solenoid I replaced on my 91 century?

Thanks

[BNaylor]

I'm assuming you had a DTC error code of P1811 or some slip code which points to the Pressure Control Solenoid (PCS). A launch shudder as you are experiencing could be caused by a flaky PCS. It is not properly regulating line pressure.

The PCS in itself is not programmed. The GM dealer can reflash your PCM module or do a reset to force the PCM into relearn mode for adaptive shifts. However, I do not believe this will resolve your issue.

Replacement of the PCS can be done DIY but not recommended. It is located on the left hand side of the valve body under the tranny side cover assembly (driver's side). The TCC-PWM solenoid is also located there.

Typical tranny shops like Cottmans will replace the PCS for around $500 to include part.

BTW - If the tranny has never been serviced try a pan drop and do the ATF (Dextron-III) and screen filter only. However, I would not recommend a flush either full or fluid exchange.

[papason]

Thank you. They did not say if they got a code and I have not asked. since they wanted to do an expensive job instead (also one I might do myself) I just said I would wait. One of my questions next time I talk to them will be how figured this. Normaly I would have asked right then but think went into shock

So you think a fluid and filter change could clear up the problem? As far as I know this has not been done.

[BNaylor]

Originally Posted by papason

Thank you. They did not say if they got a code and I have not asked. since they wanted to do an expensive job instead (also one I might do myself) I just said I would wait. One of my questions next time I talk to them will be how figured this. Normaly I would have asked right then but think went into shock

So you think a fluid and filter change could clear up the problem? As far as I know this has not been done.

Other than the shudder are you getting any other problems? Harsh shifting (upshift/downshift)? Whining?

GM recommends doing a tranny service at a 100K mile interval but I found out that 30K - 50K is better on any 4T65E tranny. No guarantee on the pan drop service but it is a good starting point. A full or fluid exchange flush would be questionable at this time with 66K miles.

Even with a pan drop you will still be able to drain out about 7.5 quarts of the old ATF. The remainder will be stuck in the torque convertor but that should not be a problem.

Tranny work can be very expensive but if you can DIY you will save a lot of money. Good luck!

[papason]

Well sometimes I notice shift into third or od seems harder than I think it should be. I wondered if there was a relation to the pcs. A while back I took to a what used to be a very highly regarded trans shop and got free check/test drive. He thought it was all normal but I think from what I have read it is hard. I read many places that these cars have such a smooth transmision shifts aren noticeable.

[BNaylor]

When a 4T65E tranny is working right they work great and the shifts are very smooth.

Really hard to say whether the hard shift to 3rd or 4th (OD) is the PCS for sure. It may not be. There are other known problems like the clutch packs and splines. Also, there are upshift solenoids. I know a tranny tech/expert on the forum and maybe he can weigh-in.

[papason]

First off thanks for being on this forum. I noticed you gave me some advice a long time ago as well. You come up often in other threads I read. This is a great site, and you help make it so. I wish I was more help to others here. Only once so far though.

Now to the point. I have not checked the price of the part but $500 for parts and labor is too much for me. You told me where it was. Do you know what it takes to replace it myself? You said panel. when I checked mine it seems there is only the end of the housing. is that the place you are refering? If it is not too involved I need to replace this myself.

[BNaylor]

You are welcome. We are here to help out the best we can.

It is a PITA of a job but can be done DIY. Since you have a GM "H" body car see how much clearance you will have to remove the side cover assembly without having to drop the engine and tranny. Also, the tranny must be drained of ATF and driver's side axle half shaft must be removed.

If there is insufficient clearance there are several key steps involved and I may be able to help out since I have done a PCS job DIY on a 4T65E tranny.