P1811

I have a 2003 Impala 3.4L 4T65E trans
The trans has started to slip ( like it is in neutral) when going from 1 > 2
Or sometimes it is a harsh shift, or sometimes smooth as silk. Seems like once up to operating temp the trans works ok. When I drive first to work maybe a slight harsh shift, that is it. After the Impala sits at work all day, coming out of the garage the 1 > 2 shift is like it has gone into neutral till the trams catches. I am thinking that maybe it is somthing external like an engine control or something causing this. I once read a while ago that some or all fords use the MAF for an approximation of how fast the engine is for a shift. So maybe GM does something the same. I could be wrong, I would think if it was the trans it would do it every time. Seems to be temp sensative.
Oh yeah I have 88k on the trans have not changed the fluid or filter, the fluid looks ok. How often should the trans be serviced ? could the filter be clogged ?

1811 relates to the PC solenoid in the valve body somewhat common issue on the fwd GM cars, have it scanned with a trans function for the proper diagnosis.

I have a 2003 Impala 3.4L 4T65E trans
The trans has started to slip ( like it is in neutral) when going from 1 > 2
Or sometimes it is a harsh shift, or sometimes smooth as silk. Seems like once up to operating temp the trans works ok. When I drive first to work maybe a slight harsh shift, that is it. After the Impala sits at work all day, coming out of the garage the 1 > 2 shift is like it has gone into neutral till the trams catches. I am thinking that maybe it is somthing external like an engine control or something causing this. I once read a while ago that some or all fords use the MAF for an approximation of how fast the engine is for a shift. So maybe GM does something the same. I could be wrong, I would think if it was the trans it would do it every time. Seems to be temp sensative.
Oh yeah I have 88k on the trans have not changed the fluid or filter, the fluid looks ok. How often should the trans be serviced ? could the filter be clogged ?

I had an issue that was pretty close to that. I took it to a transmission repair shop and they said it's a common issue. It has to do with the adaptive shifting and not being able to adapt any more.

Let's just say it cost me about $2200CDN to fix it. But the shop also did some upgrades on parts and a few electronics.

The only option is to rebuild it,had one cutomer come in with a check engine light on.It was this code and my father called a transmission shop that he knows.The transmission shop told him the only fix was to rebuild the transmission.They have ran into the code a lot and that is the fix.

Not necessarily true, the pcs can be at fault here, the scan will show slippage and gear errors to determine if the unit is slipping and causing the code to be set or the pcs has failed and the pcm is being fooled into the wrong commands.Check this link for all the info. http://townhall-talk.edmunds.com/direct/view/.ee9945e/338

There is a SMALL chance you have to do an O.H with the DTC P1811. A trans with this code 90% of the time its just the PCS, unless there is junk in the pan. The trans shop that charged you 2200 CDN did not know how to diagnose it correctly.

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

had the same problem with a 2000 impala ...change the filter and fluid....it had 183,000 miles at the time...it now has 273,000 miles on it and no problems....oh yea at the time of the filter and fluid change...I also installed a separate transmission cooler...I heard these cars had issues with temp control of the trans.

installed accumulator springs from transgo sk4t65e kit and works great, good fix

I was dreading changing the pcs, but it was easier than i thought. I am not a mechanic and I am not suggesting that you do this, this is what I did and it worked fine and saved a bunch of money and was easy to do. Anything you decide to do is your choice and I am not liable for it
1. disconnect battery and drain transmission fluid, put transmission pan back on with a few bolts, you can change the filter when you are done with everything else and put all the bolts back in
2. take off air filter housing and air intake, take electrical plug out of transmission
3. raise boot on steering gear box and take bolt out of steering connecting to steering shaft, it is one bolt and has to come completely out and then slide the shaft up off of it (this is done so you do not damage the steering when you lower the cradle)
4. loosen axle nut and lug nuts so you can get them off when you raise the vehicle.
5. raise vehicle,and support it,take off the following only on drivers side: wheel, brake caliper (hang out of way), lower ball joint off of lower A arm, tie rod end, sway bar
6. now you can take out the 3 strut nuts from up top and tap on the axle nut very lightly, then take the axle nut off to get it out of the front hub assembly,
7. push down on the lower A arm, and pull the strut out (i left the strut, rotor, front hub assembly as one when i took it out), also take out engine splash shield which has 3 plastic rivets in it, then pull out axle, i used a slide hammer
8. I had 3 different areas of support , the body, the transmission, and the front drivers side cradle
9. I placed a piece of plywood on the jack and used it to support the transmission, be careful not to raise it to high and crack your coolant reservoir
10. I placed another jack on the cradle
11. I used jack stands to support the body
12. I took out the tranny mount nuts that bolt it to the cradle.
13. With the tranny supported, as well as the Cradle, I loosened the 2 drivers side cradle bolts and took them completely out. Lower the cradle down. This allows you to get to the bottom bolts of the side cover. Then lower the transmission down to get the rest of the bolts out.
14. Pull off side cover and replace solenoids. Disconnect wire harness, they have a pin that you must pull out with needle nose pliers, pull out solenoid
15. Reverse procedure to assemble
16. got alignment

This job took about 5 hours, because it was my first time doing it, but it is real easy
I bought a solenoid kit off ebay for $108, fluid and filter for about $60, I used about 10 qts

every car is different so use common sense when you are working on it, you have no one to blame but yourself if you screw up, good luck

I too am suffering from the P1811, cars in at the tranny shop right now. Waiting to hear back after they drop the pan and give it a once over. They are suggesting either replacing the valve body, or if there are tons of shavings a rebuild. I have never had trans issues before, whats a rough estimate for a valve body change? I think they said around 1200 (cdn) + taxes, does that sound fair?

*EDIT*


Just got the call, sounds like there were shavings galore in the pan. Looks like a rebuild, ouch my pocket book.

The 4t65e was always bad about that. Read this thread http://www.automotiveforums.com/vbulletin/showthread.php?t=899929 It helped me a lot. I have the 4t65e in my 2001 Grand Prix, and the shift kit idea worked perfectly for me. It has been in my car for a little over 2 years now with no further issues. The shift kit was only about 60 dollars, and another 60 for the fluid and filter.

Site search will give you plenty of info on this, commonly discussed over the years,