QuestionQUESTION: I have a 1997 Chrysler Sebring JXI Convertible 2.5 L V6 with Autostick , it has 99,000 miles on it and currently is having Transmission problems.
Here is the history my daughter got into a minor accident with the car in the front end, we
had it repaired and when we were supposed to pick it up from the Body shop they said they had it on a charger all day but the battery won’t hold a charge, so we had to jump it to get it home. After we got it home it held a charge fine I don’t know if loosing power had anything to do with the trans. Problem but I thought I’d mention it. Anyhow after we got the car home we drove it for probably 2 or 3 weeks and then one day it went into Limp mode. As you started driving from a stop the trans would shift from 1st gear to 2nd gear just fine but as the rpms increased and it was supposed to shift to 3rd it would SLAM back into 2nd gear. It would stay stuck in second gear until you stopped and shut the car off then it would start off in 1st gear and do the same thing. I should also mention that the Autostick did the same thing you could drive in 1st and 2nd but when you shifted to 3rd the RPMs went up and it SLAMMED back into 2nd gear.
I took the car to a nearby Mechanic who installed an Output sensor(the one towards the right when facing the front of the car).The Input sensor(the one right below the radiator cap/hose)is still the original. Well the Output sensor didn’t fix it and the Mechanic recommended that I take it to a Transmission shop.
Now the transmission is just Stuck in 2nd gear Period, it doesn’t shift from 1st to 2nd , it is just always in second gear, the auto stick is the same just 2nd gear nothing else. The other thing I noticed is that before the Gear selector would show if I was in P,N,R,1,or 2nd gear, now they are all always lit up. I was going to give up and sell the car for whatever I could get for it but People have told me to try replacing the Transmission Computer(TCM). I would like some expert opinions on what people with knowledge about these transmissions would do. I went to AutoZone today and had the Check engine light code read, the ONLY code that showed up was P1698 the Definition was:
BBECM fault-no CCD message from TCM
Explanation:
BBFailed ECM
Probable cause:
BB1.-Open CCD bus line
BB2.- Failed TCM
So Do I try a used TCM from the Junk yard for $50? I heard that these may or may not need to be reprogrammed to work properly, is that true? If so can Auto Zone reprogram it or do I have to search the world for a Chrysler dealership that is still in business?
Do you think it is the TCM or the ECM (which I assume is the same thing as the PCM located by the Air Cleaner?)? I do also remember that before all of this ever happened that the two connectors on top of the PCM used to get real Hot, should they? Maybe the PCM is the problem and not the TCM? From the Fault code above and past experiences what do you guys think?
If needed My TCM P/N is P04606474AB S/N TEDTH07772BMXX
My PCM P/N is P04671259AG S/N T10EH003736610
ANSWER: Hi James,
The trans goes into limp mode either because the TCM has detected a problem with the trans that bodes further damage (and would set another code other than the 1698) or the trans relay is not closing as instructed by the TCM, or the TCM fails to communicate to the relay to close (and that might well set the 1698). There is a fuse for the TCM power that is relevant that you might want to check: #3 in the power distribution box under the hood by the battery. Also, the front-most relay in the box (behind the empty socket) is the trans relay and you might try switching that out with one of the wiper relays if they are the same part number. If neither of those prove effective, then based on the 1698 and assuming no problems with wires that send the digital data from the TCM to the BCM and to which the code reader was attached, then the TCM itself is suspect. If you get a used one from a similar Sebring convertible then the only programmed item is likely to be already set correctly: the pinion factor which tells the TCM the gear ratio of the transmission. The only thing a dealer can do, or a shop with a sophisticated diagnostic box, is teach the replacement TCM the operating characteristics of the transmission in your vehicle (which are no doubt different from that of the donor vehicle because of differential wear and tear). That is called a 'quick learn procedure'. Nonetheless the replacement TCM can learn by itself, or you can teach it slowly as it were, by going through 15-20 or so gradual accelerations with a fixed throttle to to top gear (to 45 mph) and then to a stop which the TCM will learn from. Then do 5 to 8 full throttle kick downs when going 25 mph and spending 5 seconds in 3rd and 2nd gears after each kick down as you accelerate again. So it would be reasonable to get a used TCM from a convert with the same engine/trans as yours and see if that corrects the situation.
Roland
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QUESTION: I bought a used TCM from Junk yard but havent tried it yet, the guy there swears I will have to reprogram it with the DB whatever machine or it WILL NOT work. Is this true or do I have a chance, the P/N is the same as the original and it is from the same make and model w/autostick. Are there any precautions or anything special I should do while swapping the two? I also mentioned that the two connectors on the top of my PCM used to get real hot, what are the chances that the PCM could also be bad? As far as what I've read I would have trouble even starting it if the PCM was bad. Lastly, from what I've told you about the error code do you think there is any possibility that it could be the soleniod thing on the bottom of the trans?
Thank you for all your help so far
James
ANSWER: Hi James,
I don't know of any precautions you need to take in the exchange. I am not familiar with the heat level of PCM or how hot the connectors might be expected to get, but I would not doubt that a good deal of heat is generated by the PCM in its normal operation, and because the code is not related to the PCM I doubt that is an issue at this time. As far as reprogramming, the only things that I have read about replacing the TCM are the pinion factor for the gear ratio which should be identical, and the quick learn procedure, which you can do alternatively as I described. I believe either way it will learn the characteristics of your present trasnmission, but you could ask a dealer what they charge to do the quick learn and also if there is anyother programming that needs to be done beyond the pinion factor. When the PCM is replaced you often have to do programming related to the theft-security system (serial numbers, etc.) but not with the TCM. I believe if the transmission solenoid pack were the issue you would get a different code than 1698. Please let me know what happens.
Roland
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QUESTION: Well I installed my used TCM from the Junk Yard and at first the signs
looked good the gear selector showed that the trans was in Park (all
selections were no longer lit all at once) I took it for a drive and the
speedometer and tac were both working again, it shifted nice and smooth
from 1st to 2nd and then tried to go into 3rd but once again it slammed
back into 2nd (Limp mode AGAIN). I shut the car off and restarted it which
put me back into 1st gear, so now I tried Autostick it worked fine for
1 and 2 but nothing for 3rd just like in "D"(Drive). So basically I'm
back to all the same conditions I had when the problem first occured
(speedo, tac, gear selector all work and shiftable in 1st and 2nd)
So I drove back to AutoZone and had the check engine light read again.
This time I got different codes:
P0700 Transaxle control system fault
Explanation:
ECM received a signal that the transaxle control module has a fault.
Probable cause:
Shorted or open circuit within transaxle
Failure of transaxle control module
P0733 Gear ratio error in third gear
Explanation:
The ECM has detected that the transmission input RPM does not
match the transmission output RPM under known conditions
Probable cause:
Check other service codes first
TSS error
Poor electrical connection
Internal transmission fault
So what are your thoughts now? Is there still hope or do you think
the transmission is Junk? Its hard to believe that the trans is bad
when it shifts so smooth between 1st and 2nd.
AnswerHi James,
The 0733 is consistent with the limp mode. I had another owner with that same code yesterday and after checking the shop manual sent this reply:
"About the only diagnostic test would be to measure the clutch volume indices, at a good independent shop. Abnormalities there might suggest an issue with the solenoid valve(s) but were that the case you should also have an 0870 or 0871. The shop could also do the 3rd gear clutch test to verify the speed ratio error. Those are about the only things to try to avoid the diagnosis of rebuilding. You have verified the transfluid level to be ok, correct. And also check that the shift selector level is adjusted properly to match the shifter in the cabin.
Best of luck with this. The 0700 just says another trans code has been 'set', and the 0733 says there is a speed sensor ratio error in 3rd gear."
The 1st and 2nd gear don't use the 'overdrive clutch', while 3rd does, so that is the one that is bad if nothing else can be found to cause the problem
Roland
