Does anyone have a writeup on replacing a pressure control solenoid?

I recently took my 2000 Grand Prix GT to a transmission specialist and had them read the codes after getting hard shifts occasionally in traffic. On the highway it seems fine. I suspected the problem was the PCS before taking it to the shop after researching it on here. When you shut the car off the problem corrects itself temporarily. The same problem matches a number of other threads I have looked at. Sure enough the codes read the the pressure control solenoid is bad. If anyone has a step by step write up for changing it I would greatly appreciate the help.

Thanks.

IMO you are better off letting a shop do the work but it is your choice. Here is a general procedure applicable to all GM vehicles with the 4T65E autotransaxle.

Disconnect the battery ground (negative) cable. Refer to Battery Negative Cable Disconnect/Connect Procedure in Starting and Charging.
Remove the throttle body air inlet duct. Refer to Air Cleaner Intake Duct Replacement in Powertrain Management.
Install the engine support fixture. Refer to Engine Support Fixture.
Remove the front engine mounts. Refer to Engine Mount Strut Replacement in Engine.
Raise and support the vehicle. Refer to Vehicle Lifting.
Remove the left front wheel. Refer to Tire and Wheel Removal and Installation in Steering and Suspension.
Remove the left engine splash shield. Refer to Splash Shield Replacement - Engine in Body and Frame.
Remove the stabilizer shaft links from the lower control arms. Refer to Stabilizer Shaft Link Replacement in Steering and Suspension.
Remove the left tie rod end from the steering knuckle. Refer to Steering Knuckle Replacement in Steering and Suspension.
Remove the wheel speed sensor harness connector. Refer Wheel Speed Sensor Jumper Harness Replacement (Front) in Brakes and Traction Control.
Remove the left lower ball joint from the left steering knuckle. Refer to Steering Knuckle Replacement in Steering and Suspension.
Disconnect the left drive axle from the transaxle. Refer to Wheel Drive Shafts Replacement (Left) or Wheel Drive Shafts Replacement (Right).
Secure the drive axle to the steering knuckle/strut. Caution: Failure to disconnect the intermediate shaft from the rack and pinion stub shaft can result in damage to the steering gear and/or damage to the intermediate shaft. This damage may cause loss of steering control which could result in personal injury.
Remove the pinch bolt at the intermediate steering shaft. Refer to intermediate Steering Shaft Replacement in Steering and Suspension.
Remove the intermediate shaft from the steering gear. Refer to Intermediate Steering Shaft Replacement in Steering and Suspension.
Disconnect the three-way catalytic converter pipe to the right (rear) exhaust manifold. Refer to Catalytic Converter Replacement in Powertrain Management.
Support the right side of the frame with jackstands.
Support the left side of the frame with jackstands.
Remove the transaxle mount bracket. Refer to Automatic Transmission Mount Bracket Replacement.
Remove the transaxle mount. Refer to Automatic Transmission Mount Replacement.
Loosen the engine mount lower nuts. Refer to Engine Mount Replacement (Front) and Engine Mount Replacement (Rear) in Engine.
Loosen the right side frame to body bolts. Refer to Frame Repair in Frame and Underbody.
Remove the left side frame to body bolts. Refer to Frame Repair in Frame and Underbody.
Adjust the jackstand to the lower left side of the frame.
Position the drain pan under the transaxle.
Remove the wiring harness connector.
Remove the case side cover bolts.
Locate pressure control solenoid (PCS) on valvebody. See pic.
Remove PCS electrical connector and retaining bolts.
Replace PCS.

Reverse above for reassembly.

Note: Be sure to replace the side cover channel gaskets during reassembly.



http://i5.photobucket.com/albums/y186/lizzywiz/valvebody2.jpg
EPC- Pressure Control Solenoid (PCS)

Thanks for the help. I'm not sure which route I'll take. The estimate from the garage was about $900 to have it fixed and they said that didn't guarantee anything. I have been told the same problem is likely to happen again in a year or two especially with higher mileage cars. Mine has 104,000 on it. They recommended replacing the transmission. I was thinking I would replace the PCS with the help of a few neighbors who have a pit to work from and between us, the majority of the tools we'll need to get me by until I'm ready to trade up on another one.

Again, I appreciate the help. I'll keep you posted on how it goes.

What shop is this? AAMCO charges around $600 with part in my area and will do just the PCS solenoid exchange but will limit their warranty as a result.

Be sure to replace the side cover channel gaskets or you may get ATF coming out of the overflow/relief valve after the job is done. Good luck!

The garage I took it to was local. It's called Pro-Trans located in State College, PA. The estimate was a little under $900 for a new PCS and around $1900 for a rebuilt transmission. I'll probably put this off for a couple weeks until I'm sure I have the time on a weekend to get it done, or I might look elsewhere for a garage that can do the work cheaper.

Also, if you haven't already check out the following thread in its entirety. No guarantee it will work but it could and definitely a cheaper route to go in the interim and a DIY job.

Click here (http://www.automotiveforums.com/vbulletin/showthread.php?t=920671)

Wow......that looks like it might work for me as well. I will surely give it a shot before I try replacing the PCS. If it fails I'm out 60 bucks, that's pretty minute considering they want $900 at the garage to do the job. They tried talking me into replacing the whole transmission as well. I tried the seafoam solution in a can with no avail roughly a month ago. I didn't know it could be so damaging. Instructions and the advance auto rep. said I could just leave it in there. I'll probably give it a shot tomorrow. Thanks!

Again thanks for the help.

What brand of shift kit do you recommend I purchase for my Grand Prix and where can I find it? Do you have a link to purchasing one online?

ZZP (http://www.zzperformance.com/grand_prix/products1.php?id=570&catid=105)

Thrasher (http://www.thrashercharged.com/l67_htm/shiftkit.shtm)

Good luck!

I think I'm going to go with the kit from Thrasher. It has been my experience that you get what you pay for and judging from the research I've done it falls among the middle/upper class price range for kits like this.

All kits make line pressure higher though. While I don't know a lot about transmission work, I understand the PCS giving me rough shifts is commanding full line pressure. That's why I get the jerk I do from time to time when it acts up in traffic. I know you have had good results with them, but out of curiosity how does the kit work to correct this problem?

Thanks!

but out of curiosity how does the kit work to correct this problem? Thanks!

By helping to keep the 1-2, 2-3 shift timing low or below .65 seconds. When the P1811 (max adapt, long shift) DTC sets the PCM sees an issue and commands high line pressure causing the harsh upshifts.


The advantage of the Thrasher kit is it comes with more rebuild parts like new accumulator springs and the accumulator housing gasket so the cost is relative.

I went with the kit from ZZP after Thrasher did not respond to my requests. I was surprised that the kit consisted of simple plastic spacers and no springs. The installation on a concrete garage floor was not fun, but the kit is in. I followed the instructions provided by ZZP to a T.

Still I worry about something falling apart in there after I reinstalled the pan. And on hard acceleration I get slipping now. Could it be because of the mileage? My tranny fluid was dark red/almost black. But there were no metal shavings to speak of.

I'm hoping the new problem goes away as the transmission fluid works itself completely through. So far I've only driven it 10 miles or so. Until then I'll avoid the hard acceleration and hope for the best.

Could it be because of the mileage?


104K miles is really not that high. I've done the mod on GM cars with over 200K miles and the original autotransaxle. You may have another internal issue in the tranny causing the slipping but best to run it for awhile and see what happens.

What brand and type (Dex III or VI) ATF did you decide to use?

I'm running Dextron III in it for now with the intention of dropping the pan again in a month or so and replacing it with the good stuff to get some more gunk out of there. Would a high mileage transmission fluid formula help my cause at all? Thanks!

I would almost wonder if you have fluid leakage causing the new slipping problem. I know you probably wouldn't want to go back in there, servicing transaxels on the ground with jackstands is never fun or easy, but I think if it were mine I would have another go. If I remember right, there is a paper gasket in there, and the bolts should be tightened from the center outwards much like a head gasket.

I have 135,000 miles on my trans, changed the fluid at 80k, and it shifts like it did when it rolled off the assembly line. Although I tend to be very easy on it cause I know the 3800 could rip it apart (especially the 4th clutch shaft).

After sitting in the cold all night, this morning it ran like a brand new car. Once it warmed up it went back to slipping again. I figured it must have something to do with the transmission fluid being thicker at low temperature. At highway speeds it works well, but from red light to red light you have to go easy or it slips.

The accumulator housing had a metal gasket. My main concern was the three metal lines that run from the accumulator. ZZP's instructions noted to be sure to seat them well. I pushed and pried on them and they seemed fine before I put the pan back on.

How about the filter snout seal? They can sometimes lose pressure when the fluid thins out if they aren't installed properly.

I'd go back in there man. It's probably something stupid.

The three lines just fit in to the accumulator housing snugly and if not installed right it would be hard to get the accumulator to line up to insert the retaining bolts.

How did you tighten the accumulator cover and accumulator to transaxle? What torque value and what sequence on the bolts? The gasket can be re-used as long as it is serviceable.

Some pics so we know what we are discussing.


http://i5.photobucket.com/albums/y186/lizzywiz/DSC00014-1.jpg
Accumulator properly installed with new ATF screen filter


http://i5.photobucket.com/albums/y186/lizzywiz/DSC00007-1.jpg
1-2, 2-3 acccumulator opened up

Driving it cold again this morning it ran like a new transmission, but when it warmed up it started slipping.

I opened it up again and tore apart the accumulator. Everything looked fine. I double, then triple checked the lines to be sure they fit snug and hammered the transmission filter in, then upgraded to Dexron VI fluid. As of yet I haven't driven it far enough to get it to slip (maybe 10 miles or so). I have driven it enough that I'm 90% sure the PCS problem is fixed, but I have my doubts about the slipping. With time we'll see.

As far as the bolts on the accumulator housing go I put them in every other hole and tightened them as equally as I could using a 1/4 inch ratchet. I don't have a torque wrench. Tomorrow I'll know more.

Good luck! Thanks for keeping us updated. Many people take our advice, run with it, and we never hear back whether the problem was solved or not.

Driving cold this morning it worked like new again, but after it warmed up the slipping started. I'm pretty positive things are put together inside there this time around (I think they were last time too), but it was worth a shot.

I'd like to thank you for your help. The PCS problem is fixed. I'll just have to deal with the slipping for a while until it either breaks, I upgrade vehicles, or corrects itself as the fluid becomes worn in.

On a side note, do you have any recommendations for additives I could try to thicken the tranny fluid or keep it cooler?

You sir have a bad PCS. It slips when hot and bang shifts. 104K is pushing it with the other things that go bad with these transmissions. A shift kit is not going to fix this. A repeat failure of the PCS yes it will happen but Borg Warner makes a replacement which works great with a shift kit

What does it do when you manually shift through the gears? Also, from a dead stop what happens when the accelerator is pressed at least 1/2 - WOT? In other words what happens when you floor it and try to burn rubber?

Sorry I didn't get back to this sooner. If I try to floor it it skips 5-7 times, extremely rough, before it shifts into 2nd. By skipping I mean the engine surges with no pull from the transmission to the tires whatsoever, then it catches hard as its surging and gives you a good jolt back in your seat.

Today, I put it in 1st and floored it. The burnout was successful! It operated perfectly in 1st gear, but when I put it in 2nd, 3rd, or D it goes right back to skipping again. It operates perfectly in all gears when it is cold, but once it gets up to operating temperature it slips again.

I ripped it apart after I realized that 1st worked today and found nothing wrong with the accumulators inside or out The lines and filter seem fine as well. The gaskets seemed fine also.

Any suggestions would be very much appreciated.

Thanks.

The slamming you are feeling, put in gear, hit gas, revvs, and then slams into gear, sounds like a pad PCS as Troy said. Nothing short of removing the trans sidepan and replacing the PCS is going to fix it. The good news is that I think GM updated the part which is a better desingn with lower failure rate.

By helping to keep the 1-2, 2-3 shift timing low or below .65 seconds. When the P1811 (max adapt, long shift) DTC sets the PCM sees an issue and commands high line pressure causing the harsh upshifts.


The advantage of the Thrasher kit is it comes with more rebuild parts like new accumulator springs and the accumulator housing gasket so the cost is relative.


I am having the same problem. I see that you recommend Trasher or ZZP shift kits. Each one says that there four levels of shift firmness to choose from. Any suggestions on which one to use?

Hi there. I am having the same problem on my 2001 Pontiac Grand Prix, 3.1 with 146,000 miles on it, hard shift and a whining sound coming from the engine when it heats up. After reading several threads I found that the problem is indeed a PCS problem. I'm going to take the car to scan for the error code but I am sure that is going to be the problem. I was looking in the AutoZone web page and found this solenoid, part number TCS77, is this the one that I need for my car to solve this problem? Thank you for your time!

Hi there. I am having the same problem on my 2001 Pontiac Grand Prix, 3.1 with 146,000 miles on it, hard shift and a whining sound coming from the engine when it heats up. After reading several threads I found that the problem is indeed a PCS problem. I'm going to take the car to scan for the error code but I am sure that is going to be the problem. I was looking in the AutoZone web page and found this solenoid, part number TCS77, is this the one that I need for my car to solve this problem? Thank you for your time!


I found that solenoid too, i think it's about $30 or so.. I went the route of installing a shift kit and trans fluid cooler. The car has shifted perfectly ever since. I used a shift kit from a company called TransGo, it cost me $60 and was designed to "correct, reduce, and prevent" the code P1811 (PCS). Also, switch to the Dexron VI trans fluid.

Thanks for the information Greg!!! I will look forward to that kit, it sounds from what you are telling me that it is the better solution. Is there an item number for this kit in this site that you are telling me? And also, how long has it been since you made that repair? Thanks again for the info!!!

Thanks for the information Greg!!! I will look forward to that kit, it sounds from what you are telling me that it is the better solution. Is there an item number for this kit in this site that you are telling me? And also, how long has it been since you made that repair? Thanks again for the info!!!


It's only been a month or two, but I do a LOT of driving, especially around town, where the trans has to shift a lot. Here's a link to the TransGo site where they list the part numbers. http://www.transgo.com/sk_generalmtrs.php The kit you're looking for is for the 4T65E transaxle. Looks like the part number is simply SK 4T65E.
Actually, here's a link to ebay to buy one identical to mine.. http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=260334831607&crlp=1_263602_263622&ff4=263602_263622&viewitem=&guid=e5cc9e371270a0aad3c68706feaa4b94&rvr_id=&ua=WVI7&itemid=260334831607

It's only been a month or two, but I do a LOT of driving, especially around town, where the trans has to shift a lot. Here's a link to the TransGo site where they list the part numbers. http://www.transgo.com/sk_generalmtrs.php The kit you're looking for is for the 4T65E transaxle. Looks like the part number is simply SK 4T65E.
Actually, here's a link to ebay to buy one identical to mine.. http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=260334831607&crlp=1_263602_263622&ff4=263602_263622&viewitem=&guid=e5cc9e371270a0aad3c68706feaa4b94&rvr_id=&ua=WVI7&itemid=260334831607

Thanks for everything Greg, I'll do that then. Just one more question. After installing the new kit, did you replace the solenoid anyway? Or did you leave the one you had? Just to know what to do, I miss a smooth ride in my car, and I want it to last.

Thanks again!!!

Refir to this post Antonio

http://www.automotiveforums.com/vbulletin/showthread.php?t=920671

Thanks for the post Tblake, I have read it and will go for the shift kit option. I will keep you posted.

Copy that, sounds good, good luck!

Thanks for everything Greg, I'll do that then. Just one more question. After installing the new kit, did you replace the solenoid anyway? Or did you leave the one you had? Just to know what to do, I miss a smooth ride in my car, and I want it to last.

Thanks again!!!

I didn't change the solenoid, just installed the shift kit. If you get the kit I showed you, you won't use all the parts; just the ones that you put in the accumulators. the directions are well written and illustrated.
SAMSUNG-SGH-A867/A867UCHJ3 SHP/VPP/R5 NetFront/3.5 SMM-MMS/1.2.0 profile/MIDP-2.0 configuration/CLDC-1.1

Ok, understood. Waiting for the kit, already ordered it. In the meantime I have another question. What is the difference between Dexron III and Mercon VI fluid? Because in the questions that I have made and you kindly answered, as well as other posts in this same thread, you recommend changing it from Dexron III to Mercon VI, I am going to do that, but I would like to know why is one better than the other, is Dexron III outdated? Or the shift kit requires Mercon Vi fluid? Just for educational purposes, I don't doubt your knowledge in the matter, thanks again!

Ok, understood. Waiting for the kit, already ordered it. In the meantime I have another question. What is the difference between Dexron III and Mercon VI fluid? Because in the questions that I have made and you kindly answered, as well as other posts in this same thread, you recommend changing it from Dexron III to Mercon VI, I am going to do that, but I would like to know why is one better than the other, is Dexron III outdated? Or the shift kit requires Mercon Vi fluid? Just for educational purposes, I don't doubt your knowledge in the matter, thanks again!


Better shift quality, and MUCH longer life - on average of 100,000 miles according to GM.. Check it out: http://www.sandyblogs.com/techlink/2009/05/dexron-vi.html

you recommend changing it from Dexron III to Mercon VI, I am going to do that, but I would like to know why is one better than the other, is Dexron III outdated? Or the shift kit requires Mercon Vi fluid? Just for educational purposes, I don't doubt your knowledge in the matter, thanks again!


:confused:

The recommendation was to use Dexron VI versus Dexron III not Mercon VI. :nono: Dex VI is fully downward compatible with Dex III. The older Dexron III was 100K mile ATF too.

How many weighing-in actually use Dexron VI? Wave. :wave:

:wave:

I went with the kit from ZZP after Thrasher did not respond to my requests. I was surprised that the kit consisted of simple plastic spacers and no springs. The installation on a concrete garage floor was not fun, but the kit is in. I followed the instructions provided by ZZP to a T.

Still I worry about something falling apart in there after I reinstalled the pan. And on hard acceleration I get slipping now. Could it be because of the mileage? My tranny fluid was dark red/almost black. But there were no metal shavings to speak of.

I'm hoping the new problem goes away as the transmission fluid works itself completely through. So far I've only driven it 10 miles or so. Until then I'll avoid the hard acceleration and hope for the best.

HI

How did it go? Did the tranny shift OK after the kit? I have a '02 3.1 that has been slam shifting after warm-up and don't want to pay the price to have the PCS changed out and I'm not sure I can do it myself.
Thanks, bstrom1953

:wave:

If you can change your own transmission fluid, you can install a shift kit. It's really easy.
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don't need to replace that solenoid - deposit buildup causes the problem I put some TransTune in the tranny - no more hard shifting