Chrysler Repair: 2002 PT cruiser: transmission in limp-in mode, transmission controller, independent shop

Question
QUESTION: I was driving my pt cruiser and was slowing down for a stop light but never had to come to a complete stop as the light changed, I noticed and i was gaining speed that the car was not shifting into the next gear. I let mt foot off the gas and if felt like went down in speed but was stuck kinda .... I pulled over and put it in park and it went into park. Put it back in drive and tried driving all over again, again it wouldn't shift into the higher gear. I pulled over again, park, shut off the car, waited a few minutes, restarted and tried again, the same...... Thought maybe the fluid might of been low, checked it ... It was full. Do you know what is wrong and what must be done to fix the problem? Park, neutral and drive works just not the higher gears, almost like its stuck in 2nd or 3 rd... Help please thank you

ANSWER: Hi Lisa,
The transmission controller has a built-in self-protection strategy called 'limp-in mode' wherein it will only use 2nd gear until some corrective action is taken. The best next step is to do a fault-code readout of the controller using a plug-in code reader at a socket under the dash next to the steering column. A nationwide auto parts store, such as Autozone, will often do the readout for free, or an independent shop will go it for about $40. Ask for the fault code number(s), what they mean, and what they would recommend to do. Then write back and tell me what you learned, we'll compare that to the shop manual, and go from there.
Please see the PS below.
Thanks,
Roland


---------- FOLLOW-UP ----------

QUESTION: Ok we went to Auto Zone and  here are the codes we got back, P0846 definition pressure switch rationality fault, P0888 definition transmission relay always off, P0700 definition transaxle control system fault and P0750 definition reverse (LR) solenoid circuit....they said it was a bad solenoid. Again thank you for your help.... What is your advise?

Answer
Hi Lisa,
The most specific code is the 0750 which points toward the solenoid which operates the clutch for low and reverse gear. It might be the wire that connects that clutch to the transmission control module (and you can check that before you deal with the solenoid itself, but unless there was some sort of damage to the wiring harness that is unlikely). The solenoid is one of several along with several pressure switches that are located together in a solenoid/pressure switch assembly this is mounted externally on the side of the transmission facing the front of the car (It is hidden from view by the battery and the air intake housing). The solenoids are not sold or replaced separately so the code pretty much dictates that the assembly as a whole be bought and replaced. The assembly costs several hundred dollars, but fortunately because it is mounted externally it is something that a handy-person can do him/herself.
The 0846 and 0888 most likely are the consequence of the 0750 problem, not the cause so those would likely disappear after the assembly was replaced.
If you would like a couple of pages that show how to replace it yourself let me know your email address and I will copy those from the manual and attach them to an email. But when you tell me your address either check the box to make the follow-up question "private" or if not just tell me the address but don't use @ symbol instead use "at" otherwise it will be automatically erased.
Thanks for your kind remarks. I would appreciate very much your clicking on the 'thank/rate' the expert box below. Where you see the opportunity to nominate me for volunteer of the month please click on 'yes'. You can do that again for the earlier question/answers we exchanged if you would care to do that just go back to those answers. There is a limit of 5 such nominations to be given per month by one questioner to one expert.
Thanks,
Roland