Please help, I recently purchase a 94 STS The car was in excellent condition until the transmission stopped shifting in Drive gear. It started when I pushed the cruise control button. Immediately the ‘Service Engine’ light illuminated. When I restart the car the light will stays off. The transmission will change thru the gears from first to third and when it suppose to change into Drive gear the light will illuminate and stay on, it then stays in third gear. On some occasions, on first start-up in the morning, it will change into drive gear, but it is short lived. I have taken the car into two auto shops. The first said it gave out the codes P0029, P0056 and P0094. He said it needed a new transmission. The second mechanic said it gave not codes, but also wanted to replace the transmission. Please help, I am in no hurry to replace the transmission until I am 100% convinced its totally broke. Does anybody have any ideas.
94 STS Transmission not shifting
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GrantT said:
The trans shift solenoids are kind of know for messing up and cracking. They have been redesigned. I think there is even a kit available. Anyways...
PO29- Shift solenoid B problem
PO56- Input speed sensor
PO94- Shift solenoid A problem
Hopefully...you really dont have a PO56 problem. This little bastard is about $20 but about $2000 deep inside the trans. It can go bad.
I would first go over to caddyinfo.com. In the 'how to' section it describes how to access the codes AND how to clear them. Then recheck to see which of the 3 codes is really causing the problem.
Sounds like a solenoid problem to me. Fairly easy fix with the repair kit.
Logan
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Hey Logan,Logandiagnostic said:
do you by any change know how to replace those solenoids without taking it to the dealer? I have droped the oil pan and I see them, one of my solenoids is broken off, how do I actually replace it? I bought a kit, but cannot figure out how to take the old ones out.. do I just pull them out or twist them or what? Any advice would be very very very appreciated!
Yeap...see the other post
I also was going to mention the other post-
http://www.cadillacforums.com/forums/showthread.php?threadid=3393
The solenoids are held in with little spring clips. You have to drop the valve body to get to them.
Logan
I also was going to mention the other post-
http://www.cadillacforums.com/forums/showthread.php?threadid=3393
The solenoids are held in with little spring clips. You have to drop the valve body to get to them.
Logan
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Re: Yeap...see the other post
what is the valve body? I think I know what it is but I am not sure... how difficult it is to drop that valve body? and to get to those clips? I droped the oil pan already so I can kind of see what it is and I can guess what it is but still not 100% sure if I want to do it or take it to a dealer.... I dont want to crew it up completely.Logandiagnostic said:
valve body
This image may help. I assume you have the 4T80-E trans. The clips are the #308s-
http://images.andale.com/f2/115/106/3768672/1063925435655_transol.jpg
Logan
This image may help. I assume you have the 4T80-E trans. The clips are the #308s-
http://images.andale.com/f2/115/106/3768672/1063925435655_transol.jpg
Logan
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Re: valve body
Thanks Logan, this is indeed very helpful... Picture is morht a thousand words...Logandiagnostic said:
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Re: valve body
Hi Logan, thanks for the picture last time, it was really helpful, i shanges both solenoids, today I put everything back together, put tranny fluid in, get in, start driving.... that **** does not shift at all. I mean it shifts into reverse, it shifts into some forward gear but does not change gears at all. Just keeps drivign in some gear ( I do not even know which one) even when I shift from 1 to 2 or to 3 or to D it does not do anything. I suspect I must have misassembles something, and most likely it is a long rod that is in teh valve body and that moves back and forth. it is connected to a half-a-wheel that moves that rod back and forth with another rod.... anyhow, I am lost, i was wondering if I connected that in a wrong way. Do you happen to have a picture of that part and how it is supposed to be connected... I hope I am making any sense. I would greatly appreciate any advice in regards to this as I really do not feel like redoing this whole things again without knowing what I am doing!Logandiagnostic said:
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Grant,
Sounds like it could be a solenoid but Just for grins before you do anything drastic, that is if you have not tried this already... "Reboot the car" this is done by unhooking the battery for about 5 mins, rehook and try again. The sysmtoms you discribed hitting the cruise and then the problem occurs, could be something different and this may get you on the right track. If the problem goes away, but then comes back when you hit the CC, then start messing with the CC and dont worry about the trans.
Another thing it could be is the shifter sensor that tells the car what your lever is in. Possibly it still thinks you are in "3" instead of "D"
Matt
Sounds like it could be a solenoid but Just for grins before you do anything drastic, that is if you have not tried this already... "Reboot the car" this is done by unhooking the battery for about 5 mins, rehook and try again. The sysmtoms you discribed hitting the cruise and then the problem occurs, could be something different and this may get you on the right track. If the problem goes away, but then comes back when you hit the CC, then start messing with the CC and dont worry about the trans.
Another thing it could be is the shifter sensor that tells the car what your lever is in. Possibly it still thinks you are in "3" instead of "D"
Matt
GrantT said:
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