QuestionQUESTION: Hi, I have a 2006 Hyundai Elantra w/ 125k miles on it. After the engine gets warm, the car will jerk when going into 2nd or 3rd gear (I believe third). I have drained the transmission fluid and put a new filter in, I have put fuel injection cleaner and intake valve cleaner in my gas tank and the problem still exists. I am being told that I need to replace my transmission but I have a gut feeling that I do not need to do all of that. Please advise
ANSWER: It is possible that you don't need to replace your transmission, but you'll probably need to have the vehicle looked at professionally to determine that. Your symptom can occur from a faulty input or output speed sensor, but may also occur because of an internal transmission problem requiring overhaul or replacement.
-- Check for diagnostic trouble codes in your engine control module (ECM) and transmission control module (TCM). Auto Zone may be able to do this for free for you, but I've also heard reports that some of their code readers will not read the TCM. Resolve any related trouble codes first. If you're not sure whether any codes are related, or if you just want/need more information, follow-up with the code numbers and I'll assist with what the codes indicate and how to proceed.
-- Once all relevant issues are addressed, if the harsh shift still exists, the next step is to perform a procedure called a re-learn. In this process, the TCM learns how much pressure to apply during each shift to make it happen over a certain time period. This, too, may solve your problem.
-- If the harsh shift still exists even after the re-learn, it's likely you do indeed need a transmission replacement.
---------- FOLLOW-UP ----------
QUESTION: Thank you for your response. I apologize. I meant to include in the last message/question that the "check engine" light did come on and I did have it checked. It received the code P0011, and said the following: Definition: a timing over advanced or system performance-bank1
Probable Cause: 1. blocked oil passage, 2. low oil pressure, 3. Failed camshaft actuator, 4. Mechanical timing issue.
I do apologize for leaving that extremely important information out. My fingers were just too fast at hitting the "send" button.
Just as a reminder: the jerking/hesitation/hiccup (whatever you want to call it) happens in 3rd gear only after warming up (doesn't do it if the car is running cold).
Thank you again.
AnswerP0011 is unrelated to the transmission issue-- it relates to the intake camshaft timing only. In most cases, the problem is in the variable valve timing oil control valve, but I've also seen this code caused by low oil level or sludge in the engine clogging the oil passage to the variable valve timing oil control valve and actuator.
As for the transmission issue, if you have the proper fluid level, I'd recommend taking the car to your local dealer. Explain the issue to them and have them check it. Unless I misunderstand what is happening, I'd expect they'll do a relearn as part of their diagnostic process. Unfortunately, in most cases with these symptoms (and no relevant trouble codes), the solution requires a transmission overhaul or replacement.
