Had to drive back in limp mode from JFK airport to eastern MA on Sunday in '03 GC. Limp mode is the right description. I hope no further damages were done.

Back home I read the four codes with my ELM327 Bluetooth scanner and Torque app on my android phone.

Replaced input (P0715) and output (P0731???) speed sensors today. No change. Do I need to clear the codes? I replaced BOTH sensors largely since they were cheap enough. There was a gray pasty substance on the output sensor and the input sensor was clean.

Are the specific P#### transmission codes different from the two digit codes I've seen mentioned?

I replaced the solenoid pack on this van a year or two ago.

I assume the P0420 code is unrelated to the transmission problem. Where do I go next. Scanning old threads it seems that a bad wire to either of the sensors is a likely culprit or perhaps a bad ground? battery? body ground?
other?
A woman drove me to drink and I never had the decency to thank her for it. __W.C. Fields

 

That is a looooong way to drive in second gear . A number of different things can cause limp mode - some are simple like wires, others not nearly so happy. If it were mine, I would drop the pan and get a look at what's on the bottom and the magnet. If there's only a thin layer of sludge and the fluid quality is good, that would be a good sign. But if there's metal fragments in the pan, then you're likely looking at a new tranny. You can also take it to a tranny shop to get the codes read from the TCM plus the CVIs, which will give you additional information. If it's looking like a new tranny plus the likely new cat, you will need to decide if you're up to putting that much $$ into an '03. Hope that's not the case, but you need to know before hanging on any more parts.

 

lookie here dos this help ?

 

Well, that certainly looks promising. I'm in the middle of working on my daily driver (a Ford Ranger) so it will be a while before I can try to sort out all the possible wiring issues, but the GC is my daughter's backup vehicle and she's out of the country until late July. Thanks for the lead.
coopab

 

bumping this thread as I have let the troubled van sit for two months. Have read quite a lot about limp mode and as it applies to my daughter's van it seems likely that the circuit for the input speed sensor is open. If I am not mistaken the fix is to make sure that the ground is good.

Perhaps this sounds a little like a conspiracy theory started by someone wearing tin foil but here's part of what I found:

"I noticed that a piece of folded paper was wrapped up with the EATX Controller I bought...and what do you know... it Also states that this is an Emissions related fault...

So... I call the 1-800 hotline... 1-800-866-6727 then press 1 then press 4 to speak with Miguell...
M-F 8am-5pm eastern time... he will tell you... this guy talks...!

the guy tells me a little secret that Chrysler has...

on ALL a604 transmissions... there is a splice point... to make these transmission work properly...that splices together a red wire from the Solenoid Pack, a red wire from the TCM/EATX, and a wire from where the EATX Relay is plugged in...
The TSB Addendum was sent out to the production line...
Because they where having the Same problem... Right from the Get Go...
they spliced the three wires together, capping off the remaining wire... and electrical taped the wires together and pushed them into the wire loom..."

Today I spent some time moving the battery and radiator overflow tank out of the way so I would have easy access to the transmission. I'm tempted to open up the wiring harness to try to find the mystery spot where the "three wires" a spliced together.

My daughter's van is a 2003 and the person who posted the above has/had a 1997. I imagine that there's more similarities than differences despite the six year difference but I wonder if someone more experienced than I am could advise.

 

Yup that's from a very old and very long thread posted on another forum years ago. Here's the thread in it's entirety. I'd have to agree with one of the posts. It was likely true for a few early build 3rd gen vans but was soon corrected. I doubt they were taping and stuffing wires years latter in 2003 and over two generations of vans.

http://www.automotiveforums.com/vbul...d.php?t=196775

 

That IS the very same thread from which I quoted. I have also seen it referenced elsewhere, and apparently many have gone way beyond what I have spent and ended up with a still "limping" Caravan. I replaced the transmission solenoid pack a year or two ago. Tranny has been fine since then until June 2013. When we returned from the 200+ mile limp back from JFK I replaced the speed sensors but the van remains in limp mode.
I tried clearing the codes to see if the "relearn process" would correct any errors, but van remains in limp mode.
As cv2003 suggests I don't think this van would be worth investing in a new transmission, although I could probably get my friend to do the rebuild and do the R&R myself. But that same friend tells me the wiring issue may be at the root of the problem.
I've taken lots of pictures and both ends of the ground strap are in line for a thorough cleaning and reconnection. There is a lot of plastic tape wrapping the wiring in many locations, so I don't necessarily think the "newness" of my 2003 means I don't have a bad splice in there. I just don't want to rip the entire harness apart, just the part where I'll find the splice.
The linked photos trace the harness from the place where two grounds attach at the bell housing (One is the main battery ground cable) Note dampness where wires enter the harness (arrow)

http://i1198.photobucket.com/albums/...rt/photo_1.jpg

The second photo shows where the two ground wires enter the harness. It appears to be quite wet (water, not oil) at this spot. shows same spot at photo_1 and expansion into very thick section of harness

http://i1198.photobucket.com/albums/...rt/photo_2.jpg

The third photo is where the harness has sections coming and going to many other locations. It is very thick and very spongy feeling with lots of electrical tape wrapping it. The arrow points to what looks like the wire coming from one of the speed sensors

http://i1198.photobucket.com/albums/...rt/photo_3.jpg

The fourth appears to be where the two grounds in photo #1 exit the harness and attach to the battery and the body (fender well) respectively. The thick battery cable has two smaller wires crimped onto the battery connector for a total of four grounds. Is there a way of knowing which ones may be related to the sensors?

http://i1198.photobucket.com/albums/...rt/photo_4.jpg

Photos are somewhat vague but you can click on "view original photo" and perhaps get a better idea. Where several different segments of the harness come together seems likely to be where the splice is but I can't be sure until I start in with my "scalpel."

TIA
coopa

 

If you replaced the speed sensor and you stil are going into limp in. There you need to have the CVI check and have a clutch test done. Has far as the wires, try moving them. The wire from the fender is the harness fro the PCM.

 

In that old thread they mention the EATX relay many times. By design, loss of power/ground (?) to that relay from the TCM is what puts the tranny in limp mode. May want to make sure all is well there. Maybe that splice is involved. Towards the end of that thread they at least elude to the location of the splice though they don't say exactly where it is. Not sure that would carry over to a 2003.

BTW - I am RIP on that forum. Need wiring diagrams? Send me a PM and include an email address.

 

There is a jumper wire package for the transmission, I thought it was a TSB before. But couldn't find it. But here is the part number for the jumper package. Mopar 04868959AC. If you are also getting a P0420 code for the cat. Open up the fuel injection harness and inspect. This could cause a lot of other problems too.