ghettocruiser

Hello everyone.

Got a weird problem on my Mom’s 2003 WJ, and Im really hoping someone has some input. Im panic posting this on a few different forums as she’s at the point where she’s afraid to drive it. Ive owned XJs for a good number of years now, and also a 96 ZJ. Her WJ seems like a different ballgame to me, and Im just at a loss. It also doesn’t help that its almost an hour away from me, so checking it out is difficult.

Here’s whats going on. It’s a 2003, 4.0, auto, with the NP242 tcase (I think its still called 242. Fulltime/partime box). The jeep has nothing special package wise. Just a Laredo. Pretty low miles, I think its around 50k. The motor runs great. Always starts.

The problem that she’s having, is with the trans. Every once in awhile, it will refuse to accelerate. Usually she’ll get in, and it will drive fine. Then all of a sudden, it just wont go. She’ll pull over, shut off the Jeep, start it back up, and it will go again. Last night it wouldn’t make it up the driveway all the way. She had to unload the groceries, then get back in it a little later and it was fine. She also says that when it does engage, shudders pretty good. This is only when the problem is occurring. Normally its smooth as silk.

Sometimes it has to sit for a few minutes, but that is only recently. It usually goes back to normal right away after a restart.

This is telling me a couple things. One, is that’s telling me the trans probably isn’t burnt up. Because it seems to reset. Its also telling me that its probably electrical since it can go away after a restart. I know the TPS can do crazy things…but beyond that Im guessing. TCM? Valve body? There is no check engine light or any other indication that something is wrong. I have replaced the TPS with an autozone replacement a while back due to a check engine light for the TPS. Light went away, all was well after that. I don’t recall the trans acting up before I replaced the sensor…she hadn’t had it very long before that. Previous owners are close family friends, and said they never had that problem…and I trust them.

Ive tried to replicate the problem while I was driving…no dice. Ive searched the net, but no one with the same problem that I could find. I HATE that it’s a problem that I cant figure out, because Jeeps are usually so simple and easy to work on. But this is just down right frustrating.

Anyone have any ideas of insight?

Thanks in advance!

Justin

kojoff

This may be a stupid question, but since you say that it shudders and wont go. Is the tranny low on fluid? Sounds to me like the pump is starving for fluid, so, no fluid-no go. When she stops, the fluid is draining back down into the pan and the pump can pick it up again and goes till it cant pick up anymore. Only reason Im suggesting this is because I have a 89 Dodge pickup that has a tranny drooling problem and if I dont stay ontop of the leak, ill get caught with it doing the same thing. If there is plenty of fluid, you may have a clogged up filter. Id start with the simplest things first.

ghettocruiser

Thanks for the suggestion! I guess I should have mentioned that the fluid level looks good, smells good, tastes good, etc. The first time it happened I immediatly though fluid level or burnt fluid.

I have not changed the filter and fluid yet though. I guess I could do that...just felt that how random it was, it wouldnt be a fluid/filter issue. I guess there could be some particle that randomly blocks a passage, but its weird. I will take this into consideration and maybe Ill pop a new filter in it. Just gotta figure out which fluid that trans takes. I know there was a dispute on some of the autos on which fluid to use...but that might not apply to this newer one.

J.

ol"blue

Here's some helpful info. http://www.wjjeeps.com/service/transmission.htm
And Welcome to CF.

ghettocruiser

Thanks for the welcome...and the link! I apologize for not posting in a noob thread or an intro thread. I used to post a lot over on NAXJA and a couple other XJ sites, along with Pirate. Since I never really owned a GC long enough to mess with it, never signed up. I appreciate the help!

My mom is a great lady, and times are tough enough for her. She got this Jeep from a family friend for a really good deal. The fact that its giving her so much trouble is killing me, since Im my families mechanic for the most part. Ive saved thema ton of money...and Im hoping to do it again. Just wish life was as easy as it was when I was single and living closer to home haha. Hence my panic posting. I figured Ide get as much of a heads up as I could.

ghettocruiser

Ok...caught onto a common issue that Im not sure pertains to my mom's Jeep. Someone mentioned the speed sensor being an issue. But this sounds like its more common to the trans with two speed sensors. The 42RE, which Im pretty sure my mom's has, only has one sensor. The Speedometer never seems to go out of wack. And there is no check engine light.

Would the speed sensor still be suspect? I know it doesnt take much to throw the system off...which is why I was suspectin the TPS also.

J.

ol"blue

I'd say no. We bought our '04 WJ new and we've had to have it in to the dealer twice under warranty to have the Transmission Control Module "re-flashed" because of shifting issues.
Check these TSB's for the WJ transmission issues. http://www.wjjeeps.com/tsb.htm#TRANSMISSION
Go to the bottom of the list.

ghettocruiser

I see something about flashing the TCM... But it also says:


"NOTE: This bulletin applies to vehicles equipped with a 2.7L Turbo Diesel engine

(sale code ENF) and a 5 speed automatic transmission W5J400 (sale code

DGJ)"

I guess that means it wouldnt pertain to our 42RE?? The thing just acts crazy. Sometimes it'll let her go, but it'll be super sluggish and wont want to move along easily. Other times, it'll just sit there revving. Shut it off, start it up, and it'll go again.

Starting to suspect the shift governor or the other sensor that is behind the pan.

Hate not having access the Jeep to check on things...

J.

ol"blue

They re-flashed ours. Twice. And it fixed the problem. We have the 4.7 L V8 in our '04.
I know it's very difficult to try and diagnose a vehicle at a distance, and hope you get it straightened out.
Dan

ghettocruiser

Well... The Jeep is back from the tranmission shop. Of course it didnt do it while in their posession. And their scanner didnt find anything weird or out of whack.

So...back to square one. They are doing a simple filter/fluid change (no flush), and visually inspecting things around the valve body while they have it. If it does it again when we get it back, time to start throwing parts at it. Im convinced its something electrical. Or a valve/solenoid in the valve body. We'll see I guess.

Wish the dang check engine light would come on and clue me in....

J.

berg

Just went through a similar problem.....low fluid
but I was convinced it was up!

When you get up in the morning check the trans dipstick and you will notice the fluid is at the hot mark and looks full even thought you have NOT started the Jeep yet and it is COLD.
false feeling iof it being up.Now start the Jeep and wait 2 minutes and check the stick.... you will find that the level now is down near the end of the stick or lower( I bet) appearing low. Long story short is we were low on fluid. I was checking it " cold" but checking it cold means you must have the motor running for the pump to initialize and show where the level really is. Checking the fluild "hot" means drive for 12 miles and check as "hot". As per owners manual. What the manual fails to say is that you have to start the motor and check I assumed cold meant not running. Checking without the motor running will give you a wrong reading.
The hole system holds over 14 qts but will run on less ... ask me how I know. Mine threw a low pressure sensor code ona steep hill . I dropped the pan my spin on filter had backed off 98% away from the threaded mount and was dumping trans fluid in the pan. Probably not your case but I had 2 separate problems. Spin on filter and 4 qts too low. I had drained 5 qts out when doing the filter so I put 5 back in but until I checked the level correctly I was 4 qts too low all along even before I dropped the pan.
04 WJ with 98 k...added 1 gal and good to go. ATF+4 is the fluid spec'd as well.

Ps I bought a new Mopar trans solenoid valve assembly and did not need it and they will not take it back.
Check the easy stuff first.. the trs valves do go bad but in my case it was mis-diagnosis by dealer and me.
They only checked with their scanner and did not drop the pan or check fluid level. Live and learn.

to find out what trans you have call the dealer and give them the last 9 digits of the vin... mine was the 545rfe
I think you have a 45rfe... which is also electronically controlled. The trs soldenoid valve is used 99-04 iirc.

psot up your results if you get a chance..

ghettocruiser

Thanks for the response. The fluid level was def within spec. I checked it several times since this problem started to pop up.

Oddly enough...its been perfectly fine since I posted this thread. No problems what soever. Which kinda ticks me off at the trans shop because they told her flat out it would need to be rebuilt (which I knew they would). If it needed a rebuild it wouldnt be driving perfectly fine the last few weeks.

Ah well. Just gonna keep my eye on it for her.

J.