kb0nly
Full Access Member
Yep, bottom of the dash on the drivers side by the center console, just got done tapping in my wires there for the EVIC. It is an OBDII as well of course!
Help-- Hoping to save my '04 Liberty!
- Thread starter ndhoo2
- Start date
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OHIO04KJ
Full Access Member
What exactly do you mean by this?
Ry' N Jen
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He means that he tapped into the vehicles "On board diagnostic" port- where a service technician plugs in a computer interface so they can "Diagnose" problems your vehicles problems. This plug is often used to install non factory fitted vehicle information modules.
Success! I was able to run the reader (I can't get over how easy it is, or that I was charged $100 by a dealer to do that), and came up with the following codes, none of which look very good:
P0700 Trans Control Sys Malfunction (this one actually appeared twice-- don't know if that means anything)
P0740 TCC Circuit Malfunction
P0700 Trans Control Sys Malfunction (this one actually appeared twice-- don't know if that means anything)
P0740 TCC Circuit Malfunction
valvestem
Full Access Member
Look here for all you need to know about fault codes, all Jeeps are the same:
http://www.wjjeeps.com/faultcodes.htm
ThunderbirdJunkie
Bronze Supporter
Now first off, typically when a vehicle is diagnosed, they do more than look at codes. They watch a lot of other things that your vehicle's doing.
However this could point to a malfunctioning PCM, or even simply the torque converter not locking up. There are a lot of things it COULD be, seems like it'd serve you well to have it diagnosed elsewhere
kb0nly
Full Access Member
Looks like P0700 is the common code for ANYTHING WRONG with the transmission, not terribly helpful unfortunately but it shows this on the web.
P0700 - This code indicates that the EATX (Transmission controller) has an active fault and has illuminated the MIL via a BUS message. The specific fault must be acquired from the EATX via a DRBIII tool. (Input or Output Speed Sensor failures often cause this code and are a common failure part on WJ Grand Cherokees).
That sounds like it could be as simple as a bad sensor causing it.
P0740 - Relationship between engine and vehicle speeds indicated failure of torque convertor clutch lock-up system (TCC/PTU solenoid).
That sounds like it could just be a simple solenoid problem, which doesn't even require remove the trans, just dropping the pan. I had the dreaded TCC problem on my Pontiac Montana, its just a matter of changing the solenoid, but its a pain in butt to get to on that vehicle as its in the vertical valve body on the drivers side end of the trans, you have to rip out everything from the drivers wheel well and drop the subframe down slightly. On the KJ its just toss it on a lift and drop the pan.
I would say this needs more diagnosis before you replace the transmission. On that scan tool of your friends that you used, did you also clear the codes after reading them?? I would clear all codes and drive for a few more days and see what happens.
I do also know that TCC problems can happen with fluid flow problems, been there done that, a new filter, fluid, and a flush fixed the Neon we had. The TCC error code never came back.
P0700 - This code indicates that the EATX (Transmission controller) has an active fault and has illuminated the MIL via a BUS message. The specific fault must be acquired from the EATX via a DRBIII tool. (Input or Output Speed Sensor failures often cause this code and are a common failure part on WJ Grand Cherokees).
That sounds like it could be as simple as a bad sensor causing it.
P0740 - Relationship between engine and vehicle speeds indicated failure of torque convertor clutch lock-up system (TCC/PTU solenoid).
That sounds like it could just be a simple solenoid problem, which doesn't even require remove the trans, just dropping the pan. I had the dreaded TCC problem on my Pontiac Montana, its just a matter of changing the solenoid, but its a pain in butt to get to on that vehicle as its in the vertical valve body on the drivers side end of the trans, you have to rip out everything from the drivers wheel well and drop the subframe down slightly. On the KJ its just toss it on a lift and drop the pan.
I would say this needs more diagnosis before you replace the transmission. On that scan tool of your friends that you used, did you also clear the codes after reading them?? I would clear all codes and drive for a few more days and see what happens.
I do also know that TCC problems can happen with fluid flow problems, been there done that, a new filter, fluid, and a flush fixed the Neon we had. The TCC error code never came back.
kb0nly
Full Access Member
Called a buddy of mine, he has all the FSM's, he said P0740 is...
No RPM drop at Torque Converter Lockup.
When your cruising down the road and 55-60mph what's the engine RPM? Most guys on here seem to say about the same as me, 1800-2000 RPM depending on tires and gearing. If your well over that then your TC isn't locking up correctly.
Could be as simple as replacing the TCC solenoid, fresh fluid and filter, and keep going down the road.
No RPM drop at Torque Converter Lockup.
When your cruising down the road and 55-60mph what's the engine RPM? Most guys on here seem to say about the same as me, 1800-2000 RPM depending on tires and gearing. If your well over that then your TC isn't locking up correctly.
Could be as simple as replacing the TCC solenoid, fresh fluid and filter, and keep going down the road.
ThunderbirdJunkie
Bronze Supporter
Yep, kb0nly has hit the nail on the head.
Banking on lockup solenoid
Wonder where it is on the 42RLE
Banking on lockup solenoid
Wonder where it is on the 42RLE
kb0nly
Full Access Member
Looking at the FSM it appears the 42RLE uses a pressure solenoid that does everything in one assembly, it switches the pressure to different paths to select the gears and overdrive as well as lock the torque converter.
My guess is unless its constantly revving hard at highway speed your just getting a random lockup problem from the pressure solenoid. That pressure solenoid assembly as the manual calls it is is like $138 from a few places i checked online.
Man if thats all it is then not a big deal, drop the pan, new solenoid assembly, new filter, new fluid, move on....
If not it could be a bad input or output speed sensor, which are right on the drivers side of the trans and not too hard to replace. Moral of the story, don't give up and replace the whole trans yet!
I would have liked to see a picture of the shavings in the pan, it could have been a normal discovery for most of us. Why did the shop mention it? Well maybe because they don't know what's wrong and said, hey we got to tell him we found something....
My guess is unless its constantly revving hard at highway speed your just getting a random lockup problem from the pressure solenoid. That pressure solenoid assembly as the manual calls it is is like $138 from a few places i checked online.
Man if thats all it is then not a big deal, drop the pan, new solenoid assembly, new filter, new fluid, move on....
If not it could be a bad input or output speed sensor, which are right on the drivers side of the trans and not too hard to replace. Moral of the story, don't give up and replace the whole trans yet!
I would have liked to see a picture of the shavings in the pan, it could have been a normal discovery for most of us. Why did the shop mention it? Well maybe because they don't know what's wrong and said, hey we got to tell him we found something....
Last edited:
Prospect62
Full Access Member
X2. Simple solenoid replacement and fresh fluid and filter job.
Thank you all so much for all of the helpful advice. I'm going to check the RPMs today on the highway and see how high they get, but I don't recall noticing them get that high before. The transmission guy I took it to mentioned the shavings, I think, because when I brought it to him I explained how frustrated I was that the other 2 places I brought it simply ran the codes, found errors, and told me it would cost $2000-$4000 to fix. I think he was trying to find a quick way to tell if there was actually something wrong with the transmission, versus an error in the computer system giving me a false reading. He did the work all for free, so I certainly don't fault him. My problem is it sounds now like there might be a simpler fix than taking the transmission out and replacing it, but NONE of the mechanics I went to suggested that. I know enough to know not to attempt doing any of that myself, so I guess I'll just need to hope that this transmission guy is honest and talk to him about these possibilities. The problem, though, is he had said it was $685 just to take the transmission out, and then that would get applied to any of the parts that needed to be fixed/replaced, which, in his experience, usually involved replacement of 100 or so parts that would total $1700, plus any additional parts he might find that were broken. I really don't want to get rid of my car, and I also don't want to spend $2000 on a $500 job. It would be so much easier if I had a mechanic I knew and trusted!
ThunderbirdJunkie
Bronze Supporter
Good luck ndhoo
kb0nly
Full Access Member
I would find another shop... Or even a Jeep/Chrysler dealer and explain to them your getting random problems with the torque converter not locking up and it may be the TCC solenoid, just to see what they respond with.
They can also put the DRBIII on there and see if there is any more details. Not faulting the other shops as transmissions can be a major pain to troubleshoot on newer vehicles, but they are taking the old school approach, let's just replace everything until it works!
I still bet its just that solenoid assembly, if it hasn't had any problems lately and its running about right RPM wise at highway speed you have a set code from one time that it messed up. Which brings up another point again, reset and clear the codes and see how long it takes to come back, who knows, you might drive a month before it happens, you might drive a day, never know.
Thanks. I'm going to try all of these suggestions. The second shop did reset the codes for me, and unfortunately the light came right back on that night. I'm going to check the RPMs and ask around a bit. I'll let you know what happens. Thanks again to everyone for all of the time and the suggestions. Can't tell you what a help that is to someone like me who feels so helpless in situations like this!
One small update-- I checked the RPMs on the highway last night when I was going 55-60 mph. I would say they got up to about 2300, but not above that. That's a little higher than kbOnly mentioned, but not that much. Seems pretty close to the range to me, but am I wrong? I have one more mechanic I'm going to call today. Hopefully he can help!
brucebotti
Full Access Member
ndhoo2,
Where are you located? Maybe someone here can recommend a good shop to bring your Libby to.
Bruce
Where are you located? Maybe someone here can recommend a good shop to bring your Libby to.
Bruce
I'm located in northern NJ. I actually did talk to one more mechanic today who came recommended, and he pointed me to a transmission specialist he trusts. Spoke with the specialist this afternoon and he mentioned the solenoid, etc. before I even did, and said he'd need to take a closer look, but he felt WORST case scenario was a $1700 rebuilding. That was such great news after hearing before that $1700 was best case! So, my Liberty and I are headed over there tomorrow. Wish us luck! Thanks again to everyone for all of your time and suggestions. I'll let you know how it goes!
ThunderbirdJunkie
Bronze Supporter
good luck nd, let us know how it turns out
kb0nly
Full Access Member
At 2300 RPM i would say the TC isn't locking up.
