Hi All, we have a 2001 Taurus LX (3.0, OHV, AX4S) with over 180,000 miles. Recently, my daughter was driving on the freeway at 65 mph for about 15 minutes & the car ran great. She got off the freeway to drive a few miles on city streets. After a couple miles in stop and go traffic, the transaxle light came on. A short time later she noticed the RPM started jumping up like she was revving the engine, even though she was only going between 20 to 40 miles per hour. When she took her foot off the gas, the RPM jumping stopped & the car went back to regular idle. After just a few minutes of this my daughter noticed that the car was not shifting properly, up or down. (From what she described, it sounded like the trouble was shifting from 2nd gear to 3rd & from 3rd gear to 2nd.). I posted this trouble earlier on this forum on another thread and was advised to check the fluid & change if old & burnt, and also to pull the engine codes. We changed the filter & dumped the pan fluid (it was old/dark) and put in about 6 ½-7 quarts of fluid. I then drove the car for about ½ hour on the freeway & never had any trouble. My daughter, and then my wife, each drove the car for about 15-20 minutes and they got the transaxle light flashing again along with the RPM jumping up. My daughter had the shifting trouble again as well. *Important to note: through all of this trouble with the flashing transaxle light on the dash, the RPM jumping, and trouble shifting, the check engine light has never come on. However I hooked up my little code reader but it didn’t show any trouble codes at all. I borrowed my brother’s code reader, which is a little better unit than mine, but it didn’t show any trouble codes either. All I can imagine is that our code readers do not have the ability to read transmission codes. Does anyone know if transmission trouble codes will cause the ‘check-engine’ light to come on? If not, how do you know to look for them? Do I need a special code reader for transmission codes? Anyway, I could sure use some help and advice on what it is, and if I am looking at something simple or a whole new transmission (remanufactured/rebuilt). Would a valve body change fix this, or a new torque converter? Thank you all for the help given in the past, and thanks in advance for the advice to come.
your code reader will only do engine codes. It will not do transmission codes. You need
to send it to a transmission shop for those codes or spend another $500.00 - $1000.00 for the code reader that does transmissions. A transmission fault will not set an engine code. If your RPM is going up and down your transmission could be slipping. Until you get the code for your transmission you will not know what the trouble is.
Your local Ford or Lincoln dealer should charge around $100 dollars to access the code. Maybe a little more for them to tell you exactly what is going on if further diagnosis is needed. This is a small price to pay for certainty as guessing can get very expensive.
It does not sound like a torque converter is the cause.
(Expensive)It could be an internal component in the valve body or transmission.
(Less expensive)However I would not be surprised if it was the MLP switch. Manual Lever Position switch. This is the switch on the transmission shift linkage where the shifter cable attaches to the trans shift lever. The switch (or connection at the switch) can cause the RPM to flare up if it is faulty. Essentially it would confuse the computer (PCM) because it will not know what gear it is in causing erratic shifting and notable RPM fluctuations.
Hi All, I had a day off so I found a transmission shop that would do a code read & diagnosis for free. Anyway, I drove the car to the transmission shop, and made a couple of stops along the way trying to get the symptoms that my wife & daughter experienced to reoccur. NO luck. The car ran fine. When I got to the transmission shop I gave the auto-tech there the list of symptoms. He got out his code reader and just like mine, no codes came up. He asked if we had reset the codes recently because he said it was showing "incomplete". (we had looked for the codes a few days ago with my little code reader, but there was nothing there to reset). Then we took a short drive with the tech behind the wheel. Of course the car ran and shifted great. When we got back to the shop he was thinking it could be just overheating and in need of a good size trans cooler.(it has been VERY hot in southern cal the last few weeks) The tech got out a different type of code reader, for transmission codes, and then he said it came up with a 4th gear ratio problem. He showed me the display, but is was in the sun so it was hard to read. But it did say something about a 'gear ratio'. He told me that unfortunately it meant taking the tranny out to fix internally. And as always, if the tranny has 180,000 miles it would be wise to rebuild it (for $1,800 bucks - but this is southern Calif so I am sure things cost more). He said the car will run like it is for a couple of months, but that it will get steadily worse. He also said he is busy for the next few weeks and could not work on it now. I asked about installing a 'shift kit' and he said the extra pressure would help. However he said you have to take the transmission out to install the shift kit. So, anybody know if this sounds like it is the problem? Anything else I can check?
Forget the shift kit. If you remove it, rebuild or replace it.
If this was the code:
P0734 Gear 4 Incorrect Ratio
then most likely it will need to be disassembled.
It may be a failed seal on the piston. The piston may have damage; either/or. There is another possibility of the tubes or lines that move the fluid through the transmission has some sort of failure-- o-ring, pinhole, etc. Of course this is just an educated guess and I may be incorrect, but it was not uncommon to see one of these overhauled every two to three weeks. In any case it sounds like pressure is dropping off when it should not. The fluid and pressure behind it essentially meshes things together and causes them to spin. No pressure= no spin= no movement.
Jasper Transmissions is pretty competitive with their quality and warranty if you want to search out a rebuilt one.
Another thing, and not to be critical, you say you and the mechanic could not duplicate the symptom, however it would occur when the ladies drove it. Drive it again and floor it. See what happens then. I bet it will act up. Another option is to ride along while one of the girls drives it. Get them to make it do it. Be conscious that people will alter their driving habits when others are in the car if there is a situation. Inform them that it is important that the symptom be duplicated to diagnose and not to judge.
The AutoGuide.com network consists of the largest network of enthusiast-owned enthusiast-operated automotive communities.
AutoGuide.com provides the latest car reviews, auto show coverage, new car prices, and automotive news. The AutoGuide network operates more than 100 automotive forums where our users consult peers for shopping information and advice, and share opinions as a community.