95 SL2 down shift issue

[LynndY]

I have a 95 SL2 that down shifts at will and them will not upshift until you come to a complete stop or shut off the ingnition, which can be an issue when pulling into freeway trafic. I have changed oil,cleaned all electrical connections. Problem has been around for 30K miles. Now car has 190K.
Any Help?????

[RC1488]

And your just now looking into this!?!?! Ahhh! :P

Replace your Engine Coolant Temperature Sensor ASAP!!! New ones are brass. Takes about 15 min. Your car has two sensors, you need to replace the one with the 2-wire connector. Do this on a cold engine.

Also, replace your tranny fluid and filter ASAP!. This should be done At least every 12K - 18K miles.

Tranny filter replacement from the top:
http://youtube.com/watch?v=Dfh9HGU3NXM
Please note the fluid MUST be drained before removing filter

ECTS replacement:
http://youtube.com/watch?v=JC0U53w_Htk
NOTE: Dealer is a safer place to buy sensor. $14.50

[LynndY]

Ok, I replaced both temp sensors and changed the oil today.
No change in the random downshift.
One thing to note. The electric fan will not come on automaticly.
Only by turning on the AC will the fan start. It will continue to run with the AC off until the temp comes back down to the 1/4 mark on the guage.
Time for a new ECU????
LY

Originally Posted by RC1488

And your just now looking into this!?!?! Ahhh! :P

Replace your Engine Coolant Temperature Sensor ASAP!!! New ones are brass. Takes about 15 min. Your car has two sensors, you need to replace the one with the 2-wire connector. Do this on a cold engine.

Also, replace your tranny fluid and filter ASAP!. This should be done At least every 12K - 18K miles.

Tranny filter replacement from the top:
http://youtube.com/watch?v=Dfh9HGU3NXM
Please note the fluid MUST be drained before removing filter

ECTS replacement:
http://youtube.com/watch?v=JC0U53w_Htk
NOTE: Dealer is a safer place to buy sensor. $14.50

[RC1488]

The s-series PCM RARELY goes bad. I have yet to see any PCM that needed to be replaced.

Note: Proper operating temperatures for your car are 1/2 as per the guage. Anything less while on the highway with the a/c off indicates a bad thermostat. The fan will not turn on untill 1-2mm before the red. Yes this seems wierd however that is how the calibration of the guage was designed. In '96 they changed the calibration so that normal operating temperatures as per the guage were at 1/4.

Here's what i would do next in the following order:
1. Remove a cable from the battery for 3 min and replace it. This will reset the PCM and make it relearn your driving habits and other sub systems of the tranny.
2. Try to remember what the connectors to the ECTS looked like. They should have had no corrosion on them at all. If they did the connectors need to be replaced.
3. Check the charging system. The tranny is very sensitive to the proper voltages needed to operate. You can bring this to your local auto store or you can do it at home with a multimeter follwing this video:
http://youtube.com/watch?v=g5B54xX_QVg

[LynndY]

I have preformed all you recommended in the order described.
All connections look ok.
Voltages 12.62 at rest; 14.56 unloaded running 14.46 loaded at idle.
The car seemed to be ok for about 25-50 miles (I don't use it much right now) but today it was back to down shifting with almost no load and then not upshifting without shutoff or dead stop.
Note: just before it down shifts there is a hesitation or stumble??

[RC1488]

Very wierd. This is the first instance ive heard of something like this. I fear that a new valve body or line pressure soleniod may be in order

Unfortunetly everything seems fine charging wise. Youve replaced the ECTS and have changed the tranny fluid and filter. All have proven no results. I fear my knowledge is at and end :/

Few options i suggest:
1. Go to the following forums, register and post your issue along with the info we have gone through here in the tech sections of the S-series section. Post the problem, vitals of the vehicle, and what you have done (filter, new ects, etc).
Saturnfans.com
saturnspot.com
Both have very knowledgeable people

2. I have a feeling one of the following sensors/pieces may be fualty however they normally would set a code (Vehicle Speed Sensor, Input Turbine Sensor, or the Throttle Position Sensor). All are used to determine the gear the car should be in. The TPS is the one most likely to be fualty with no SES code. Be sure that when the key is in the RUN position BEFORE you turn it to turn on the car, that the SES Light is on. This means the bulb is good. Sometimes one can have a code and the bulb is burnt out so youll never know it!

3. Line pressure Soleniod. This is one of the 5 soleniods in the tranny. If you feel so inclinded you can replace this following this video
http://youtube.com/watch?v=JUSSj_2eHUY

Unfortunetly I do not know which one is the problem! One of the other members of the forum may tho. Ill be following along since im very curious as to the issue!
Again sorry I could not help. Good luck!

[Scrapper]

souds like time for new bands or tranny module..that means overhaul it i would think...sorry good luck tho....