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Transmission help needed

smokinum

New member
Has anyone had problems with their transmission shift selenoids ? My 99 prix will not kick itself down and kind of stumbles at about 60-70mph. I have heard some whinning coming from the trans. but it is intermintent. any thoughts would be appreciated.:confused:
 


I kinda have the same problem. Mine doesnt shift down though. Shifts real hard and i get a whine like a S/C. I found that turning the car off for 30 secs then starting it right back up resets it. Does yours have that prob? If so electrical???
 
These problems should both be in the 4T65E section for future referrence.
-Smokinum you could have a number of problems and when shift solenoids fail on these cars there will generally be a code in the history for electrical or mechanical solenoid failure. You really should have an experienced transmission diag guy drive your car with a scanner and see what is going on to verify proper operation and find out what is causing your problem. These transmissions are completely electronic / pcm controlled so a number of circumstances will case the transmission not to work properly such as engine sensors not working right.
-SilverMist01 your problem sounds like a failing pressure control solenoid and is very very common on these transmissions. The harsh shifts and loud whining is the result of the pcm commanding max line pressure to cover up your problem and is a failsafe to keep the trans from burning up. If you check your codes you will likely have a P1811 in the history. This code will not turn on the SES light and will reset with a key cycle and the car will drive normal a short period of time again just as you say.
 
Thanks Trannyman but sometimes i can drive for hundreds of miles and not have one bad shift or any whinning sound? Still the same problem?? Also is it bad to drive on it like that?
 
When the trans is whining and shifting hard it is a bit more harsh on parts but it isnt really hurting anything to where you need to be concerned that it will fall apart or cause excess damage. The idea is to prevent slippage and burning up the trans. Without scanning your car to view data it is hard to say exactly if that is your cause and that is why I always suggest taking the car into a trans expert for a good diag to determine the cause of the problem. Generally when a pressure control solenoid is going bad it will act up after the trans warms up or you have driven for a short while. Going down the highway for a long time is not going to make the problem happen because you are not cycling through shifts starting off in 1st gear while cruising along. It may take the car until you come to a stop after this long highway jaunt and making a few shift cycles before the problem exists and at that time it will see slippage during the shifts and throw the code and max out the line pressure and you will hear the noise and feel the harsh shifts.
 


This post from me will explain both problems going on in the two trans's To the owner with the 99 if its not kicking down then the shift soleniods aren't reading what the pcm's doing. You need to have a trusted and experienced trans shop not a guy drive the car with a scanner and a internal pressure gauge hooked up to the car to monitor every angle of the trans when its working. And to silvermist hard shifting is bad very bad in a trans thats not working right. to make sure whats going on take your car to a trans shop and have them scan the car on a drive and see when the pcm commands the shifts and see how long or slow it takes the pcm to react. Also have them hook up a pressure to monitor the internal pressure because shifting hard is a sign of a spike in pressure. and a gauge will tell you so sure if its spikinig at the shift points. Good luck with the two cars fella's keep us posted
 
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