I had buy a sts 95 few month ago with 70000 miles (112000km). I saw, when I went home with car that the shift was hard and I had changed the shift solenoide + filter + oil of transmission






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The shift was always hard after, especially from N to D and from 1 to 2.
I had 2000 miles to do, and last week the Over-drive was out, and the transmission went at first gear only. Stop and start car, and now I drive with 3.
When I want go at fourth, the transmission get at first after few secondes. I think it's a safety mode.
Now I have buy a scanner and put it at car to check and appear this:

94 shift ratio A problem

It mean that I must chang the solenoide, but i have already to do this...

What can I check or chang? The speed sensor ? ECM? Other?

Ah, and my transmission didn't smell burn, and oil was on good condition before chang it, and filter was already chang before buy car.


I have this too at scanner:

76 force motor malfunction

But this, I don't understand.

 

You don't need scanner - scanner built into this car. See FAQ about On Board Diagnostics. For trans concerns it is limited, if you can get a Factory Service Manual, possibly from Quebec, Canada (it may be in french) it will help alot. When solenoid kit was installed were all parts installed? Bracket in kit keeps filter from blowing out eventually breaking solenoid; typically you will loose 4th gear first and shortly afterward lose the other gears.

 

The 76 force motor malfunction refers to the PCS(pressure control solenoid). This solenoid is in the side cover of the trans...not in the bottom, as the two shift solenoids that you replaced are. This code is most likely the cause of the harsh shifts, but any trans code will force the trans into a "limp home" mode, which raises the working pressure of the trans, in an attempt to keep it from burning itself up due to a malfunction.

The 94 shift ratio A problem does not mean the solenoid is bad, or needs to be changed again. It only means the PCM commanded a gear that did not take place, such as the 3rd-4th shift. This could be because of a defective solenoid, a stuck valve, a hydraulic problem(internal leak), or even a wiring harness problem.

The two filters you changed(in the picture) are "scavenger" filters. The main fluid filter is in the side cover of the transmission. Removing the side cover with the transmission in the car is almost impossible...it's actually easier to remove the trans for any service work in the side cover...

You should also check the transmission electrical connector for corrosion, and/or terminals that have pulled out of the connector. This is a fairly common problem.
I also heartily recommend the Factory Service Manual if you plan on doing any service work yourself...they Service Manuals are invaluable in helping troubleshoot all of the things that can/will go wrong.
hth

 

First, thanks for answer.

You mean pressure control solenoid like at this picture ?



About Factory Service Manual I had bought this:



It's great book, but not so much information about transmission..




Yes I have put the small filter + new bracket too with solenoid.

 

Yes, that is the PCS in the diagram.
The Haynes manual is ok, but they tend to cover too many year models to be very specific about anything.
I would suggest unplugging the transmission electrical connector, and checking for corrosion, or any wire damage. The connector is hard to get to, but it is in an area that gets a lot of heat, and moisture, as well as engine oil from cam covers leaking.
I could e-mail you the diagnostic routine for checking the PCS, as well as the wiring diagram for the trans/vehicle, if you need.

 

Oh yes, this would be great !
My mail:
memez@mrachassis.com

Oh, and I will check all connection this week end, and prepair order at rock auto for PCS and some other things.

And something else: I had put DexronII (ATF 220) and may be it's not the right oil? Dexron III (technosynthèse) will work better?

After look at web this evening, I have understand exactly what you have meaned. In fact there are 2 valve body @ this transmission, one at bottom and the second on side...
Ok,ok I reading somewhere that it's possible to remove cover by only move in car the engine/transmission.
I will chek first wire I think..

 

Any Dextron fluid is fine...no need for any "special" fluid for the 4T80E. Dextron III is the most common fluid, so that will work.

Info is in the (e)mail to you. Just need a couple of minutes to get it uploaded....

 

I have disconnect this connector today, to clean it. It was full of transmission oil inside!
I had clean with airline, then dry it and connect. Put scanner, clear code, then drive, but problem stay always here...

 

How it was better the old style transmission! nothing elctrical inside...

 

I receive these following parts from rock auto:
-Main filter
- Pressure control solenoide
-TCC solenoide
-TFT sensor
Now, I look the best way to get out (under the car) my tranny to remove the side cap...