QuestionQUESTION: Dear Roland
I've encountered some problems with my transmission (dodge Grand Caravan 3.8 AWD year 2000).
I've already exchange transmissin oil twice (once with filter) Oil was dirty and brownish but smells normally -(not burned).
I've exchanged Solenoid Pack (brand new)
I've checked by OBDII reader - but no transmission error codes (question: is it possible to check and read codes by standard OBDII reader codes from transmission? or it is possible only by DRBII)
My main problem is:
When I start my car in the morning (engine is cold and aslo transmission oil is cold; ambient temp. 15 Deg Celcius)
Engine works fine, idle approx 900~700rpm.
And after changing from PtoR or NtoD or NtoR (and all other combination when cold - engine stops idle - dies,
-Then I start again engine try to put gear once again sometimes is good and I can drive - no problems all day(until next morning)
- or sometimes I must afer changing gear to D or R quickly release brake - car is driving going forward or reverse.
If in last case if I push brake pedal just after releasing brake pedal Engine will stop idle. But I if I push brake pedal after 100m of driving it will be no problem all day long)
I was visiting couple mechanics (they dont have DRBII or DRBIII scanning tool) - first diagnosis Solenoid Pack (it's echanged now).
Now they telling me Converter.
But This is guessing not diagnosis.
Please support me with some clues or good advices.
Thanks in Advance.
ANSWER: Hi Krzysztof,
The trans fault codes should be accessible by any good OBD-II reader. The behavior you describe would appear to relate to the torque converter clutch control. There is a code 1740 that would corroborate that problem. The issue with it could be in the valve body of the electronic transaxle where there is a switch valve, a control valve and a regulator valve all three related to the torque converter clutch. As the valve body can be removed and serviced without having to take out the transmission from the vehicle my inclination would be to inquire of a qualified shop whether they believe that the symptom could be due to an issue within the valve body or not, and if so what is the cost and likelihood of that repairing the problem; and if not, then that implies an issue inside the torque converter proper and the cost/likelihood of that repair. So if there is such a shop I would engage them in a discussion about servicing those valves in the valve body as the first approach.
Roland
---------- FOLLOW-UP ----------
QUESTION: Thanks a lot fot a prompt answer.
I've checked for fault codes on more than 5 different readers, but none of them shown any of fault code from transmission.
So if there is no code 1740 it is most likely converter?
ANSWER: No, I would not conclude that no code means it is the converter itself that is at fault. I don't see specific electronic controls of the valves that are involved so it could very well be there is dirt in one of those three valves. I don't think it would be prudent to pull the transmission and change the torque converter without dealing with the valve body as the possible cause. And because you can remove that, by dropping the oil pan (and saving the trans fluid for reuse if possible) and removing the valve body, I would want to hear a valid argument for not doing that first. It is a tricky removal in that a couple of other valves can drop out when you first remove the body so you have to watch carefully to see where they come from and their specific arrangement, so I would only trust it to someone who is trained/experienced with the Chrysler electronic transaxle. Get a second opinion as I am not experienced in the actual task at hand.
Roland
PS By the way, there are two codes for the torque converter malfunction (0740 and 1740) and they both occur in association with a failure of the TCC to set up properly, not to its failing to release. So again, the failure to release may be more likely related to an hydraulic failure due to a sticking valve, I would surmise.
---------- FOLLOW-UP ----------
QUESTION: Is it safe to drive without repairing this issue immediately?
Could it cause major damage to the transmission?
AnswerSo long as the lock-up doesn't manifest itself at high rpm (high idle speed) so that the torque on all the parts isn't too great, I would believe it shouldn't cause damage. It is basically like starting a manual shift car in gear with the clutch out, or jumping off the clutch when it is idling. But don't shift out of park or drive at high rpm.
Roland
