[h2oman]

Hello all, sorry for the long post... i have a 2003 CTS with 99,500 miles on it. ever since i bought it at 73,000 miles, the trans seems to be having 2 issues (maybe related). 1) when accelerating, the first couple gears are perfect and smooth, but when the car gets up to operating temp, and i accelerate to between 15-35mph and the rpms get btwn 2500 and 2900, and i let slightly off the gas but not all the way, it seems that the fourth gear and torque converter engage almost simultaneously and the rpms drop too low (around 1300 or less) and the car shakes/bounces. if i let off the gas completely or keep on the gas just before it's about to shift, it wont bounce and the two shifts seem to be separated. i believe it is not related to the final fifth gear because it does the same thing when i keep the shifter in "4", not "D". i had the fluid changed at around 92,000 and the torque converter and flexplate replaced at around 96,000, but neither fixed the problem. I see there are software updates, but they do not pertain to '03 models, only '04 and up...any ideas?
2) when coasting to a stop, it feels like the trans is staying in gear too long which cause some annoying shifting patterns... i heard the car uses "engine braking"...but does the car use it more when it senses the brakes getting worse? (i think my pads are getting low...)
could these issues be related, and be program fixable, if an update even exists? could i have a bad MAF sensor or speed sensor, or any other bad sensors (currently, no dtc codes)... thanks in advance and sorry for the long post...

 

[ghettomike]

are you in sport mode for these?

try it out of sport mode for a day. the sport mode is designed to "learn" the drivers driving patterns and shift accordingly. im not sure how to reset it but there should be a way.

 

[h2oman]

No, i'm not in sport mode. I rarely like to use sport mode because it seems to shift all over the place, or doesnt seem to know when it should shift. I do use it when i want to go from 70mph to 80 mph real fast, but rarely... i tried unhooking the battery over night to see if that would do anything, but it didn't.

i took the maf sensor out the other but couldn't tell if it was bad, it looked really clean to me... does anyone konw if a software upgrade exits for the '03s?

 

[Flavoade]

Could be the solenoid that controls it. Do you have extended warranty? I had my transmission replaced at 49k. It began shifting stranger than normal one night. When it shifted into 5th it would grind. They totaled it and gave me a another one, but it is no better.

 

[h2oman]

do you happen to know how difficult of a task it would be to replace the solonoid? is it inside the trans? are there any speed sensors that are associated with the transmission? i had an extended warranty which covered the torque converter and flexplate...but it ran out a few thousand miles ago.

 

[Flavoade]

Not sure where it is. I think it is on the outside by the transmission, or somewhere under the hood. There are guys on here who have diagrams that can pin point it. Wait, I have service manuals. I will check them out.

 

[Flavoade]

OK. I glanced over it real quick. I do not fully understand it yet, but apparently there are 3 solenoids that control the gears 1-2, 2-3, and 4-5. There are other solenoids that control and monitor pressure and other things. All functions of the transmission seem to be controlled by the TCM. From what I see in the book, the shift solenoids, and a few other things are located on the driver side of the transmission, close to where it connects with what ever is in front of it. The book shows that there are other transmission controls under the center console, located by the shift lever. It also shows that there are two units located under the hood by the fusebox.

I do not have time right now to read it more thoroughly, but I will study it more closer tomorrow night and tell you what else I find out.

But from what I can see, changing the shift solenoids is not that hard. I say that now, but for all I know you might need a special set of tools.

 

[h2oman]

Has anyone else had or heard of this problem? it seems that when lightly letting off the gas while still accelerating at around 35mph, it shifts into fourth gear and tcc engages almost at the same time, causing an annoying bounce feel. either tcc engages too soon, or fourth gear shifts too late. is there a fix?

also, is there any way to eliminate the engine braking? stays in gear too long when slowing...

 

[Flavoade]

Is it a bounce or more of a jerk?

I have not forgotten about you. Instead of reading it and trying to describe it you, I have decided to make a PDF file with the pages in it. Challenge is, there are more than 300 pages on this piece of junk transmission. If I had a choice I would have gotten the 5 speed Getrag.

Skimming over a few of the pages, I noticed that most of the trouble shooting procedures require data tools, like an OBD II. Once I finish the document you should be able to tear the transmission down and put it back together again, if you want to.

 

[Flavoade]

Have not forgotten about ya. Having scanner problems. Will try to get the PDF to ya as soon as I can.

 

[Coke_O]

I'm having transmission troubles too. Mine shifts really rough, upshifting and downshifting. I always have the P0700 engine code on. Any suggestions? The car also idles really strange. It idles up and down and then i get an "Engine Power Reduced" message and a "Service Idle Control" message.

Help please.... diagrams would be very helpful.

 

[gpet6669]

That doesn't sound like tranny problems to me! That sounds like an engine Idle Control problem.

 

[Coke_O]

I have already changed the throttle body (throttle body sensor is attached). What else can I do? It still idles out of control and drives too rough.

 

[gpet6669]

I would say it could be as simple as a fuel filter and/or air filter, or as complicated as a computer issue with communication or registering air fuel ratios. (Might be a bad O2 sensor)
Which brings me to my next question. Is it throwing any other codes? Besides the P0700 code(Transmission Control System Malfunction).

If it is just the transmission then I would say it would be a corroded wiring or a bad trans controller or computer.

 

[Coke_O]

The other codes that come up are:

C1278 - TCS Temporarily Inhibited by PCM (what does PCM mean?)
P0121 - TP Sensor Circuit Insufficient Activity
P2135 - Throttle Position (TP) Sensor 1-2 Correlation
P2176 - Minimum Throttle Position Not Learned
P0700 - Transmission Control System Malfunction

When I clear the codes, it works fine for a few minutes. Then, all of the codes come back on and it starts idling crazy.

 

[gpet6669]

There is your answers, the throttle position sensor is probably bad.

 

[Coke_O]

But i just replaced the throttle body along with the position sensor (it is attached to the throttle body).

 

[Coke_O]

I purchased it new. could it be anything else?

 

[Flavoade]

Good news H20!:bouncy:

I have figured out how to use the big Xerox workcenter at work, and should have the tranny pages for you tomorrow night, if all goes well.

 

[gpet6669]

I would check in the book, there should be a flow chart of all possible things to check for each code. If you don't have a chiltons book or something comparible then I would get one. It may not be the sensor itself, it could be a wire or anything inbetween to include the computor itself.
Have you cleared the codes from when you last replaced the parts? That will make a difference. (Just making sure, I don't want you to take it the wrong way! I don't use the right words sometimes to say what I mean to say)