While driving the transmission shifts out of overdrive. Shifts out of third and the torqueconverter will engage and disengage. The RPM will fluctuate 100 RPM several times and will jump to 3,000 RPM on the open road. The transmission was rebuilt. The tests were done but the transmission is doing what the computer is telling it to do. This does not occur all the time. This jeep has a 318 engine and is full time 4X4. It has 177,000 miles on it.
My 1999 Jeep Grand Cherokee Limited was just returned to me after some brake work and now when i accelerate it pauses for a second then goes then accelerates bumby from 1-2 then again a little slower from 2-3 and will not change over to 4th, why?
- If you need clarification, ask it in the comment box above.
- Better answers use proper spelling and grammar.
- Provide details, support with references or personal experience.
Tell us some more! Your answer needs to include more details to help people.You can't post answers that contain an email address.Please enter a valid email address.The email address entered is already associated to an account.Login to postPlease use English characters only.
Tip: The max point reward for answering a question is 15.
P0740 JEEP - Torque Converter Clutch Circuit Symptoms - Engine Light ON (or Service Engine Soon Warning Light) - Transmission shift shock - Vehicle may not shift into the highest gear
Possible causes - Low transmission fluid level - Dirty transmission fluid - Faulty torque converter clutch solenoid valve - Torque converter clutch solenoid valve harness or connectors - Torque converter clutch solenoid valve circuit is open or shorted
When is the code detected? Torque Converter Clutch (TCC) unlocked for 10 sec., ECM commands converter lock-up and did not record engine speed drop.
P0740 JEEP Description The torque converter clutch solenoid valve is activated, with the gear in D4, by the Transmission Control Module (TCM) in response to signals sent from the vehicle speed and the Engine Control Module (ECM). Lock-up piston operation will then be controlled. When the torque converter clutch solenoid valve is activated, the torque converter lockup clutch will engage creating a 1 to 1 RPM ratio between the transmission input shaft and the rotational speed of the torque converter.
Lock-up operation, however, is prohibited when A/T fluid temperature is too low.
When the accelerator pedal is depressed (less than 2/8) in lock-up condition, the engine speed should not change abruptly. If there is a big jump in engine speed, there is no lock-up.
you may be confusing the torque converter clutch engagement with o.d. this trans has a problem with the T.C.C. regulator valve wearing out the valve body bore. this will cause the converter clutch to engage only sometimes or not at all. this will set a P1870 code in the control module. when this code is stored in the controller, ( check engine light may or may not be on), it increases the pressure in the transmission causing the 1-2 shift to be harsh. ask a local tranny shop to scan the vehicle ( most will do this for free) if this is the problem they can either fix your valve body (sonnax parts) or replace it with an upgraded valve body. hope this helps
You have a short to ground in the internal wiring harness.The first thru third shifts are done hydralicly.The SMEC then applies a ground to the overdrive solenoid for fourth gear and the TCC solenoid for torque converter lockup.
I have a 2001 base impala and 6 months ago I experienced the same problem. I was driving on the street and all of a sudden my car acted as if it was in neutral. I pulled over and neither of the shifts engaged. The dealership said that my torque converter went bad. Somehow the bad torque converter caused shavings to get into my transmission. They gave me a new torque converter and flushed my transmission. My transmission was almost 2 years old; therefore, it was under warranty.
lets start with a transmission flush and filter change. then have you checked any of your vacume lines. A bad vacume line is the number one thing that causes any form of transmission mis shifting. When it gets warmed up the lines alow cracks to open up and mess up the function of the vacume line. Also you need to have the torque converter checked. You also need to have a computer scan on the vehicle. a bad sensor or coputer could cause any of these problems.
let me know what happens when you check these out.
I would look into replacing the VSS which is the vehicle speed sensor, it is the input that tells the transmission when to go into overdrive and the torque converter to lock up, also make sure the connector is clean and tight to the sensor, this part is located on the side of the trans where the speedocable would go.