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Help with trouble codes P0129 and P0884

17K views 6 replies 5 participants last post by  07GrandCherokee 
#1 ·
I have two codes displaying in my DTC when I run it through the cycle, need some help deciphering them if there are any experienced folks or Jeep mechanics who can help me out.

Looked up the codes on the only source I could find, wkjeeps.com and found the following:

P0129
Barometic Pressure Out-of-Range low
MAP sensor input voltage out of an acceptable range detected during reading of barometric pressure.

For the above, sounds like my MAP sensor may be in need of replacing? For $18 I'm probably not going to waste the time to clean it... but that is only because time is not something i have to spare these days or I'd try that first. The Jeep has been stalling intermittently when coming to a stop when she's driving it, can't duplicate for the life of me when I'm in the car / behind the wheel of it. She failed to tell me about this when it started occuring 2k miles before the standard warranty ran out... I think I've said all I need to say on that topic.

More importantly code P0884 - I CAN'T FIND A THING ON THIS ONE. Can anyone provide any input? The chart on wkjeeps.com doesn't even go up to 0884... suspect it may be related to the tranny fluid issue but I've been keeping a close eye on the level. It just showed up today for the first time though.
 
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#2 · (Edited)
P0884-POWER UP AT SPEED (CONTINUED)
For the Transmission circuit diagram (Refer to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC - 45RFE/545RFE -
SCHEMATICS AND DIAGRAMS)
For a complete wiring diagram Refer to Section 8W.
When Monitored:
When Powertrain Control Module initially powers up. Due to the integration of the Powertrain and Transmission
Control Modules, the transmission part of the PCM has its own specific power and ground circuits.
Set Condition:
This DTC will set if the PCM powers up and senses the vehicle in a valid forward gear, with no PRNDL DTCs,
and an output speed above 800 RPM, approximately 32 Kmh (20 MPH)

Theory of Operation
If a vehicle loses power to the Transmission Control System, the solenoids (LR, 2C, OD, UD, 4C) will go to their
respective power off state. Some solenoids are normally vented and some are normally applied in their power off
state. The transmission is designed to be in 3rd gear with all of the solenoids in this state. However, if power is
restored, the Transmission Control System will power-up and normal operation will be restored.
This code identifies that power to the Transmission Control System was restored when the gear selector was in a
9Drive9 position while the vehicle was moving at speeds above 32 Kmh (20 MPH). This DTC does not indicate a
problem with the transmission or Transmission Control System, instead, it suggests intermittent problems in
the fused ignition switch output, fused B(+), or ground circuits to the TCM. Alternately, if a person performs a rolling
restart maneuver, the DTC can be set. Therefore it is critical that this DTC be investigated if the vehicle is experiencing
intermittent 3rd gear operation and a subsequent return to normal operation.
Diagnostic Test
1. CHECK FOR INTERMITTENT POWER AND GROUND CIRCUITS
This DTC is set when the Transmission portion of the Powertrain Control Module is initialized while the vehicle is
moving down the road in a valid forward gear.
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors.
NOTE: Due to the integration of the Powertrain and Transmission Control Modules, the transmission part of
the PCM has its own specific power and ground circuits.
Check all of the Fused B(+), Fused Ignition Switch Output, and ground circuits to the PCM for an intermittent open
or short to ground.
With the scan tool, check the EATX DTC EVENT DATA to help identify the conditions in which the DTC was set.
 
#7 ·
Check out the info in this thread. It will give you the short version of my suspected eventual diagnosis, and a long version of my horrid ordeal with the POS.

My best advice would be to try the following:
Don't fill you gas tank for a few weeks, stop a few gallons short of full basically, and see if it goes away. We drove our Jeep for something like 2-3 months like this while we waited for the lawsuit to settle, and it never stalled once. Filled the tank to where the pump shutoff just once by accident, started stalling again randomly for the next few hundred miles.

Had I not been out of patience with the thing by then, I would have pursued having the gas tank replaced - but by then it was game over for me and Jeep.

Best of luck to you all with this same problem - I hope you find the diagnosis steps provided help narrow down the culprit. Do us all a favor if it works, whether or not you pay a dealership to fix the issue, please go in and tell your dealership that these codes and this problem were related to the gas tank. Drop a letter to someone technical at Chysler and let them know as well. Strange problems exist everywhere, but all I'm saying is it is a damn shame that the ONLY resolution I found to this problem came from a former Chrysler engineer hanging out on a GM forum I'm on after ditching the other Chrysler in my fleet for a GMC and mentioning the problem somehow. If it wasn't for that guy, this miserable problem would still haunt my mind despite it being over a year since I dumped my Jeep.

And while it's definitely not brand bashing, I personally like the products offered by Chrysler, but my opinion is if you're not going to sell a quality product you should at least take the time to make sure all of your highly skilled techs are aware of the faults of your vehicles. Please, don't take that as a knock to a single tech or engineer working on these vehicles post sale, but simply as in addition to my frustration, I saw the frustration on the faces of the guys who tried their best to fix my Jeep and if you're a mechanic of any sort, you know how if feels when you have to "give up" and no one was happy in this ordeal.

And again, not to brand bash, but I've found the grass is sometimes greener on the other side. Ditched a Ram for a GMC and have 25k miles without a hint of a reason to make the drive back to the service department where I bought it from worth the free oil change it came with. Ditched the Jeep for a VW (definitely an apples to oranges comparison - it's job is to get the wife to work in the snow which it does, but doesn't haul the boat like the Jeep did) and 18k so far without a single complaint or issue yet. If you tallied up the number of visits each Chrysler vehicle before it had at the same mileage, you'd do what I did - never look back.

Best of luck to everyone - if you don't mind, I'd like to hear whether your problem was the same source as mine and how it gets resolved so keep the thread going please.

Greg
 
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