L200 2.2 2001 hard shifting weirdness

[Solion]

Transmission problem
2001 Saturn
L200 4 cyl Front Wheel Drive Automatic 156000 miles

Okay I have a Saturn L200 with the 2.2 4cyl, 156k miles on it, Never had any problems until recently.

I can tell exactly when the problem is going to happen. Both fans on the radiator/AC come on and are at 100% balls to the wall running,. if in drive, it hard shifts like crazy as if I am in some sort of limp mode. I can hand shift it and get stopped somewhere safe.

Now if I restart the car 2 or three times, the fans will on one of those trys will turn off and everything is fine , smooth shifting, the same perfectly good car as I have allways known and will drive normally for a week perfectly .. then WHAM , it does it again and I have to go through the routine of limping to a stop somewhere.

I got nothing, I have gone through the wiring harness, I hope to hell it isnt a BCM mayby a TPS ? has anyone heard of this? No check engine light and no codes what so ever. Some weird Idling as well.

[radioouman]

Some people around here have had bad throttle position sensors. I am just about to replace mine due to some shifting weirdness too.

I have not had the same experience with the fans, but I have had some incredibly hard shifts until I shut the car off and start it back up. Not sure why. Hoping that it is a malfunctioning TPS.

[Robman]

I'd say take a look at your intake temperature sensor on the intake tubing. that could be a possibility.

[KickenChicken]

Originally Posted by radioouman

Some people around here have had bad throttle position sensors.

yep, symptoms sound familiar and that was my culprit!

[fdryer]

It might be worth at least one transmission oil and filter replacement and carefully checking battery voltage and cable connections. Have the battery tested thoroughly and if in doubt replace it. The same for the battery cables, check them for severe corrosion on the terminals and if in doubt replace one or both. The last electrical issue would be checking the alternator and serpentine belt drive system. Eliminate the easiest from the difficult; battery, cables, alternator, and belt drive provide essential power to everything engine/transmission driven. Electrical power is useless if not delivered through clean cables. The alternator actually provides all the electrical power the engine and transmission needs but if the belt drive system isn't maintained then the battery is called on to supply power. This isn't supposed to occur as the battery is basically used just for starting and the alternator used for engine/transmission power. Eliminating power from this leaves open the possibility that a transmission problem may next. Since the transmission gets its cues from the engine and sensors, any engine issues should be addressed before looking at the transmission. A general overall view of the engine should help determine if engine issues are affecting the transmission.

The fans turning on is a clue that may suggest electrical problems (battery, cables, alternator, and belt drive system) that can be caused by failure of good power in sufficient quantity. Less than 12v battery power or less than 13.5v alternator output can overwhelm the EFI system to run efficiently. Be sure of checking the easy stuff first before turning to possible transmission issues.

[Solion]

Changing the TPS today. Idle has been abit high at random times, so I may replace the idle control solenoid if the TPS does not fix the idle problem.

I got a lead that indeed the TPS may be the culprit from another forum, that the bad sensor confuses the ECS and throws it into limp mode to keep from distroying the engine/tranny (bypassing temp sensors fans full on) there has also been mentioned replacing the MAP sensor at the same time. This has stymied allot of shops from what I hear, and caused transmissions to be dropped and rebuilt/ CPS replaced for no good reason.

This has been a fantastic car, hopefully I wont need to replace the CPS

Stay tuned!

[fdryer]

You're getting side tracked. If the engine runs the cps is working.

[Solion]

Okay replaced TPS aaaaannnd drum roll please

Wow that changed things, over the past few weeks I have been super sensitive to every shift point and sound the car makes. One of the alternate problems was a random high idle at stop lights.. SO changed the TPS and what happened..

a) Transmission shifting is 15% smoother. downshifts are normal.
b) more power, She moves like she should. throttle is more responsive.
c) High Idle issues are completely gone.

as for (D) transmission hard shifts /limp mode/fans at 100% this will take time, but if we are good over the next couple of weeks Ill say it is fixed. Replacing the TPS (30.00 at Autozone) made a real and tangible difference.

Overall, If you are having the "fans on high/ hard shift" issue. Id say change your TPS (only 30.00 and easy as hell to replace) and see if if things get better. Overall since this problem does not throw a code ( or a proper one) it coulden't hurt. and could save you a trip to the tranny shop.

I will update here if the problem persists with hard shifting. or at least post if the problem has gone away for a minimum of 2 weeks

[KickenChicken]

Sounds like you may have found the problem.

[Ex-GMtech]

Did you clean the throttle body when you replaced the TPS? Just a good idea to do it and it could help improve things a little bit more. If you start having the shifting issue again, replace the pressure control solenoid(PCS) in the trans. It might also be a good idea to replace the trans position switch(internal, not the one on top of the case) while in there.

[Solion]

As promised a semi final update.

Since the replacement of the TPS shifting has been fine, no sign of the high idle /fan on full and fuel economy has gotten allot better. I went and cleaned out the throttle body when I changed it.

Soooo Im gonna call it fixed. we are good to go. I hope this will save someone a trip to the transmission shop. and stupid mufflerbearing BS repairs

I really must say that the ecotec engine is pretty frigging reliable. now after 2 trips I am on 160k and it has not a tick or rattle to be found. Sounds liek it did when I bought it. it starts at 1/2 second twist of the key. (Mind you regular oil at 3000 miles and transmission fluid changes every 60k, coolants flushed every spring. has helped) Actually keeping it clean works as well.

[Abdelage]

I also had all of those symptoms - hard shift, cooling fan always on high, strange idle speeds. A code shows that my IAT Sensor was defected. (Intake Air Temperature Sensor). My mechanic narrows it down to a defected split wire at the sensor. It first look it did not look broken, but inside the insulation the wire was split. As you gently pull on the wire, the insulation stretches. My mechanic got a used part (plug) at a local junk yard and wired it back. He cleared the code (you can do that by disconnecting the negative terminal of the battery for a few minutes) and voila…run like a charm. Pass it on.

[SeriouslyJim]

Solion... you are a genius!! I have the same car, the exact same symptoms, even similar mileage. Here we are, six years from your original posts and still the local mechanics cannot figure the thing out. I only wish I had found your post BEFORE I replaced the transmission... Oh, well... the correct fix- the TPS- cost less than 1% of the transmission we had already thrown at the issue. Imagine our dismay when, after a week of perfection with the new tranny, it did it again and started getting worse. Yet, we couldn't get it to fail when the mechanics could look at it... and even when it set a soft code, it again disappeared before the mechanics could look at it. FRUSTRATING!!
Anyway, thank you for taking the time to post your experiences. I can honestly say that without your post, I would still be tearing out my (thinning) hair! And you are also the first for whom I ever have registered on a site just so I could say thanks. Also, you've probably saved a Saturn from an early grave...
Take care!!

[gymflake]

Just experienced the exact same problem, including the fans coming on! I bought the certified AC Delco TPS and Wala!!! Fixed the problem and then some! Never shifted so smooth, although I have only had the car since February. Inherited from a original owner mom's friend for $500.00! She kept all the maintenance records from day one!!! Great tip! My mechanic was very impressed that I did some research but you did the real work!!! Thank you!!!

[joshnabs]

I had similar issues with weird shifting over the past couple months. Two days ago I thought I was loosing the tranny. Not wanting to up shift and not find fourth gear on the highway. Limped to a parking lot for my daughters softball practice and debated a tow 15 miles home. Thankfully I had a couple hours and found this forum. Turned off the ac for the drive home with no major issues. Yesterday I bought a new TPS and spent more time finding the right tools than it took to change it out. Today I drove it 80 miles and it shifts noticeably smoother and no issues with the ac on. What I thought might be a repair worth more than the car turned into a 40$ fix. Thanks everyone for posting! I think I will drop the pan and service the tranny as well when I have the time.

2001 l200. 156,000 miles