Hi All

Any ideas welcome as I'm just about to throw my hat in on repairs for this jeep.

It's an automatic transmission 2007 (2005 model) CRD KJ with 55K miles.

No problems with engine and just standard repairs over the past 3 years. Have loved this jeep as it really gave me no big issues over the last 3 years of ownership.

Over the last month the Torque converter and transmission pump failed and I've gotten both these replaced.
Got a TC from florida torque and the new style mopar transmission pump.

I've been driving it for the past week with these new parts and its been going great. Shifting gears without any issues and I've been listening to it like a hawk but all seemed well.

Today was the first day I hooked up the empty horse trailer (circa 1000lbs) to it and that's where the problems have started.

Straightaway it's giving problems shifting. It started driving forward ok but when I put it into reverse with the trailer on nothing happened. It didn't even sound like it was shifting. I high revved it for a couple of seconds without it going anywhere and then when i let it off it seemed to shift and i could move a little. But then when i then shifted into drive nothing again. Thought I was stuck but turned the engine off and on again and straightaway the jeep reversed no problem. But when i put it into drive and then reverse again, same issue pops up.

When I took the trailer off and started driving without, the jeep is shifting fine...forwards and reverse no issue.

Before I consign it to the scrap heap is there anything else I should look into first? I've just spent a lot of money on it over the last month but it's useless to me if I can't tow with it. I was thinking perhaps solenoid or valve body? But really at the moment I've no idea but i'm no gonna put too much more money into it.

Anyone else ever dealt with these symptoms? Thanks in advance

That's really odd. No warning lights or anything? Did you try pulling the trailer with electrical disconnected?

I tried pulling the trailer both with the electrics connected and without. same issue.

i ran a scan on my obd scanner earlier in the week when i got the jeep back with the new transmission parts installed and had driven it a couple of days to check and there were no codes on it.

i've just run it again there now after trying to pull the trailer and there's loads of codes on it:

p0733- something unusual with the ratio of the third gear in the vehicle's transmission
p0731 - greater than a specified RPM difference between the rotational speed of the Input RPM Sensor and the Transmission Output RPM Sensor in Gear 1
p0846 -anomalous fluid reading from the transmission system
p0876 - problem with the transmission fluid pressure
p0841 -Transmission Fluid Pressure Sensor/Switch “A” Circuit Range/Performance
p0501 - vehicle speed sensor
p0700- malfunction transmission control system

After clearing all the code I would try to unhook the battery for a bit to get ECM and TCM to reboot.

They usually have a learning time at the beginning.

Doesn't cost anything to try !

That's a lot of codes!

Clearing the codes and disconnecting the battery sounds like solid advice.

Also, that crazy wide range of problems makes me think there's an electrical issue. Maybe a bad connection to the TCM or the main transmission harness? Not sure why it would change depending on whether there's a trailer on the back though. Maybe dumb luck?

I've cleared all the codes and disconnected the battery. will leave it sitting overnight and do some experimental driving with it tomorrow to see how i get on.

it doesn't make financial sense to pump much more money into because of its age but it will break my heart if i have to walk away as it's always been great to me up to this point.

Will your code scanner pull live data from the TCM? Being able to watch for anomalies might be useful.

The code tables in many scanners aren't accurate for the CRD (shocking surprise that Chrysler did their own thing) but here's the results from our code table in the tech section:

P0731-GEAR RATIO ERROR IN 1ST
P0733-GEAR RATIO ERROR IN 3RD
P0841-LR PRESSURE SWITCH RATIONALITY
P0846-2/4 PRESSURE SWITCH RATIONALITY - --or--
P0846-2C PRESSURE SWITCH RATIONALITY
P0876-UD PRESSURE SWITCH RATIONALITY
P0501-VEHICLE SPEED SENSOR 1 PERFORMANCE --or--
P0501-VEHICLE SPEED SENSOR PLAUSIBILITY
P0700 is a generic "there's a transmission code MIL request" for the generic OBD scanners that can't talk to the transmission.

This COULD be electrical in the solenoid pack... But how's your battery voltage? When the computer starts throwing this many problems, it can usually be traced back to a power issue that makes the computer's math go nutty. With low enough voltage, 1+1 starts equalling "bullfrog" instead of 2.

_________________
Proud supporting vendor of LOST Jeeps
TRAVELING CRD TECH. I come to you!
Need help? Just ask! I've taken it apart more than most.
Email jeep [at] maincomputer [dot] com - BOARD MESSAGING IS BROKEN
Over 125 CRDs currently driving with my timing belt, rockers, or ARP Studs.
Bad noises = REALLY bad things.

Generally "gear ratio errors" happen when the data from the input speed sensor and output sensors don't match the math in the ECM. That falls in line with the VSS errors. All those pressure switch rationalities reinforce a connection or voltage issue... One sensor with a rationality problem is likely to be the sensor, but two you're looking for something upstream probably.

Hard to determine the cause and effect here. System voltage makes a lot of sense as a broad explanation, although I think most cars actually have a P code for low system voltage... Maybe the CRD doesn't though!

I assume you have towed with the Jeep before, yeah? This isn't the first time you connected the trailer electrical harness?

There IS a performance code for low voltage, but by the time it is finally set, you are usually on the side of the road or sitting in a parking lot unable to turn the starter or maybe even unlock the doors remotely. I.E. by the time that code sets, you are already VERY aware of the problem.

Perfect example: I had the serpentine tensioner pulley bearing fail on me last week while I was 100 miles from home and returning from a 3k mile road trip. Spat the pulley right off the front of the engine and spun / shredded the belt into EVERYTHING around. Of course it was at night too, and towing. After cleaning up the debris, I got in and drove home. No A/C, no power steering, no alternator... And NO idiot lights or codes.

These things don't know DIDDLY about setting codes properly.

_________________
Proud supporting vendor of LOST Jeeps
TRAVELING CRD TECH. I come to you!
Need help? Just ask! I've taken it apart more than most.
Email jeep [at] maincomputer [dot] com - BOARD MESSAGING IS BROKEN
Over 125 CRDs currently driving with my timing belt, rockers, or ARP Studs.
Bad noises = REALLY bad things.

good thing it was only 100 miles at about 140 miles you would have run the battery dead without the alternator.

_________________
05 Blu LIM, OME GDE Tbo, wk II 245/75/17, KC Lights, bull bar, 195K H TC
05 Blu Lim, Dayton, GDE HT, 255/75/18 , 210K , H TC
06 Bla Lim, GDE Eco, Destination AT 245/75/17, 151K, H TC
06 D Khaki Lim 126K wkII Eur TC
05 D khaki Lim 145k refurbishing
All CRDS: Fumoto, Lift , Fan Shroud mod, fuel head Gen II, SAMCOS,self TB, 2 Mic filt, Hayden

so its giving the same problems now without the trailer hitched. whether it was just bad timing or the extra weight of pulling the trailer triggered the problems i don't know.

i cleared the codes and left the battery disconnected all night. started it this morning and did a little driving but it still started giving problems and going into limp mode.

charged the battery up even though the meter on the battery said it was ok.
drove a little and error codes still came back but not as many as above.

however as i was about to park it up, i was taking a left turn in forward drive and she just shuddered and the engine cut out. could hear some noise coming from underneath. started it up again and was able to reverse...so thought i'd try again. but again when i went to drive off around thr left turn she cut out once more. so i started it and reversed it back to a parking spot and walked away.

could it be something with the computer not recognising the new transmission pump? or could the transmission pump be the wrong part? i bought it on ebay but it came in its mopar box with correct part number on it.

or maybe my mechanic messed up something when he was putting them altogether although he said everything went fine with it.

plus the fact that i almost got a weeks driving on the new parts without any issues is strange.

Well, at least now things make more sense.

The order in which the codes come back will probably be telling. You need those codes, some live data, and probably a physical pressure measurement to go further.

TBH, it still sounds electrical... without proper feedback from sensors you can get some real goofy stuff happening, like for example torque converter lockup at low speed which stalls out the engine.

Right now everything is suspect- the new parts and the work - you need the aforementioned data to learn more. Will your scan tool get live data from the TCM?

no i've just got a basic scanner that will read and clear codes.

i really can't afford to throw any more money at it at present as i need a vehicle asap to get to work. so i'm off to look at a 2007 grand cherokee and a 2007 laredo tomorrow. maybe i'll get this looked into more in a few months when funds allow as it kills me to know its got a great engine with low mileage for its age and with little else wrong with it other than this transmission issue.

What was the original issue that led you to get the pump replaced? I mean, is it possible the condition was misdiagnosed, or the shop that did the work blew it? From working great to not working in a few minutes raises a lot of questions.

was driving it one day and the transmission just went...pressed the accelerator but no power so she rolled to a stop at the side of the road. when my mechanic started taking it apart there was metal everywhere and the transmission pump was falling to pieces

i had noticed a shudder when driving around 60mph before that but hadnt read anything about the TC problems and thought it was something else. it wasn't causing me a huge issue so i kinda ignored it. obviously the tranmission had been failing for quite a while

I'm going to try and get it to a scanner over the next weeks/months to see if there's anything that can be done to salvage it.

I've got a couple ideas for you, not entirely sure that they apply (things learned from different transmissions)

1. The dumb one that I don't see asked: Have you checked the fluid level? The dipstick might be wrong too. If it's low enough to suck air it will do some strange things. I've also heard these really need ATF+4. A lot of RWD transmissions will work just fine with Dextron 3, so some mechanics just put "tranny fluid" in them. (I haven't tried dex3 in one, so I'm just going from what I've heard)
2. Same line, but more complicated: I think these have the deep pan right? I'm not sure the differences on these transmissions but I fixed a Allison once that had a deep pan and shallow filter. It just dropped out of the rubber seal and went into neutral going down the highway. If our pickup is lower you just might suck air at odd times? (usually it would just drop into neutral though...)
3. If you pull the TCM fuses you should be able to shift between 2nd, 3rd, and reverse manually with no power at all to the transmission. If it still acts up it's almost definitely not electrical.

What I would do is this:
Check the fluid level, running in neutral (I think park is ok on this transmission, but the 4xRE's don't fill the TC in P unless they've had the Sonnax thing installed, do it in N if possible just in case I'm wrong),
If it's good get the transmission into limp mode (pulling fuses is probably easiest), then see if you have 2nd, 3rd and reverse. You shouldn't have lockup or any shifting besides what you do with the lever. If it doesn't work like that in limp mode it's mechanical or hydraulic, not electrical.
If it still acts up add 1qt of fluid. Maybe 2 tops, Understand that if the fluid level is right and you add 2 qts it will likely be high enough to hit rotating parts foam up and make a huge mess if you drive it far. You have to get it back out, so plan on dropping the pan or get a sucking thing to pull it back out of the dipstick hole. (the idea is if it's sucking air due to a filter issue this will raise the fluid level a bit)

Other possibilities include something coming apart in the transmission itself, or a tiny piece of metal making it into the valve body and jamming something...
Also there's a spin on filter in the pan. Seems like someone had it loosen or break off once, but I don't recall the symptoms
Some transmissions like to plug the cooler in the radiator when they fail, that can cause TC lockup problems if I remember correctly... (the big problem is it cuts off the lubrication circuit on some...)

The stalling really worries me, it sounds like the TC is going into lockup when it shouldn't, so yea, that's not good...

_________________
2005 Jeep Liberty Sport CRD 4x4 278k

The transmission fluid level is good. a little over the higher mark as recommended for these jeeps. it's brand new atf+4.

before the pump and tc were replaced, the transmission pan was dropped and the filters were changed. when the pan was dropped a lot of metal was found in it and my mechanic cleaned it all off including all off the valves and solenoid unit. we were initially hoping this was the cause of the original problem. when that was all put back together and didn't work we knew we had to go deeper.

i've just done a little more testing in it.
cleared all the codes.
started it up and left idling until the temp came up to normal so i could check the fluid level.
put it in drive and she shifted into drive.. drove forward a few feet.
put it into reverse and went back a few feet.
put it into drive and forward
reverse once more.
drive once more and she started shuddering and stalled...so that sounds like TC lockup yeah?
the only code it's throwing now is p0841

i really don't understand how it could drive so well for a week after the new parts were installed and then boom!

i'm wondering if it could it be a sensor or a filter in the transmission tray fell out or something...

the transmission tray will be the first port of call when i decide to get something done with it...but i doubt if i'll go ahead to get the transmission dropped again in a hurry...too much cost at the moment

Yea, that sounds like TC lockup. It shouldn't be doing that. It's likely a valve sticking somewhere. (could be pretty much anything that lets fluid pressure get where it shouldn't though) Some are in the valve body (you can drop that without removing the transmission), but the TC valves are in the pump housing. The problem is a piece of lint or a human hair can cause problems in a valve body.

I think that code is for pressure in the Low Reverse circuit getting pressure when it shouldn't. That would fit with valve body problems, but could also be a damaged teflon or something somewhere.
I'd pull the fuses (or tcm) and make sure it still does it (and therefore isn't electrical).

Then drop the valve body and go through it with a fine-toothed comb (and a case or 2 of brake-clean). I don't know if I recommend that though, you have to get it back together right and have a very clean place to work on it.) I've done it on other transmissions, but there are lots of springs and stuff, easy to mix things up.

If that doesn't fix it it's pulling the transmission out again. That's the worst part of working on transmissions (for me anyway).

Anyway, I hope you can get it sorted, good luck when you have time to mess with it!

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2005 Jeep Liberty Sport CRD 4x4 278k

If there were metal shavings in the pan originally, and only the pump and TC were replaced when it was removed, I wouldn't be surprised to find more metal floating around in there. Getting the TCM out of the equation (pull plugs, TCM, or fuses) makes great sense... see if it works mechanically to rule out the TCM asking for things it shouldn't be.