2007 Self Shifting Into 4WLow & 4WNeutral - Jeep Garage - Jeep Forum

Go Back   Jeep Garage - Jeep Forum > Jeep Platform Discussion > Grand Cherokee - WK > Troubleshooting/Problems

Reply
 
Thread Tools Display Modes
 
  #1  
Old 01-13-2015, 11:01 AM
New Member
 
Join Date: Jan 2015
Posts: 2
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
jeeper999 is on a distinguished road
2007 Self Shifting Into 4WLow & 4WNeutral

Couple months back, driving about 40mph and Jeep shifted into 4WLow. Able to pull over and get it out of 4WLow and took to dealer. Service 4W lights on but no codes showing. They changed front/rear differential & transmission fluids. Did recall flash upgrade (N23 I believe). Did it again a few weeks later and took back. Dealer told me I needed $1800 transmission work (I think trying to fool this lady). Took Jeep to local transmission shop and they said nothing wrong with it. Shifted itself again into 4WLow and also showed ABS/ESP lights - found local mechanic who changed out front wheel bearing sensor which was corroded. Fixed ABS/ESP problems, but same day it shifted into 4WNeutral while driving about 40mph then shifted into 4WLow. Again, got out of 4WLow and back to mechanic. Codes say perhaps a problem with transfer case but he's not sure. $900 for used one at junkyard. Jeep has 170K so I'm sure stuff is corroded/worn, but hoping someone has guidance before I keep replacing parts they "think" are the problem. Suggestions?

Reply With Quote
Sponsored Links
Advertisement
 
  #2  
Old 01-14-2015, 07:02 AM
Frango100's Avatar
The beast from Brazil

My Jeep: 2004 4.7L WJ
 
Join Date: Dec 2009
Location: Brazil
Posts: 7,615
Thanks: 23
Thanked 424 Times in 409 Posts
Rep Power: 529936
Frango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond repute
Re: 2007 Self Shifting Into 4WLow & 4WNeutral

It sounds strange for the dealer to mention transmission problems, while its the T-case which is shifting to 4Lo and Neutral.Eventhough the problem could be mechanical inside the T-case, it could also be a problem with the Final Drive Control Module (FDCM). As a test, i would ask the mechanic to disconnect and stow the T-case control motor connector and drive for a while and see if it doesn´t go to 4Lo nor Neutral. You can get a message " service 4 WD", but just ignore it with the t-case control motor disconnected. If it doesn´t go to 4Lo anymore, then most probably the problem is with the FDCM, wiring or the T-case switch.
Ofcourse driving like this is a bit tricky, because suddenly shifting to 4Lo when on speed, will cause a large drag and engine overspeeding.
__________________
Frank

JEEP Grand Cherokee 4.7 Lmtd 2004
HID 8000K in low and fog / Quad Squad member
KYB Gas-a-Just shocks / Pirelli Scorpion ATR 245/65/17 - Transgo reprogramming shiftkit.

VW Beetle 2.0 TSI 2013
My new toy
Reply With Quote
  #3  
Old 01-14-2015, 10:52 AM
Member
My Jeep: 2005 5.7L WK
 
Join Date: Jul 2010
Location: Kingston, Ontario
Posts: 970
Thanks: 3
Thanked 43 Times in 42 Posts
Rep Power: 278082
dr.lee.baugh has a reputation beyond reputedr.lee.baugh has a reputation beyond reputedr.lee.baugh has a reputation beyond reputedr.lee.baugh has a reputation beyond reputedr.lee.baugh has a reputation beyond reputedr.lee.baugh has a reputation beyond reputedr.lee.baugh has a reputation beyond reputedr.lee.baugh has a reputation beyond reputedr.lee.baugh has a reputation beyond reputedr.lee.baugh has a reputation beyond reputedr.lee.baugh has a reputation beyond repute
Re: 2007 Self Shifting Into 4WLow & 4WNeutral

How do you know it is going into 4-Low?

I think if you were able to shift into 4-low at 40MPH something is very wrong. There are all sorts of electronic checks to make sure a proper shift procedure is followed, and shifting into low range at 40MPH is not one of them! That must have been near the upper limit of what the Jeep could even do in low range.

Dropping into neutral inadvertently is what the N23 recall is meant to stop.

I think the advice above is good, and agree that something electrical is likely the culprit. As mentioned above, I would hold-off on changing out the transfer case until you are sure that is the problem...much of the shift logic is in the FDCM and not the transfer case itself.
Reply With Quote
Sponsored Links
Advertisement
 
  #4  
Old 01-14-2015, 01:05 PM
New Member
 
Join Date: Jan 2015
Posts: 2
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 0
jeeper999 is on a distinguished road
Re: 2007 Self Shifting Into 4WLow & 4WNeutral

Thanks for the advice, this is what I was looking for. When it shifted itself into 4WLo, not only did it grind as it was doing so at 40mph and I felt like someone smacked me from behind, but then the 4WLo light was on - when going through the normal procedure to take it out of 4WLo, it worked. The second time the 4WNeutral light came on as it was grinding into neutral at 40mph then switched itself right into 4WLo and that light came on. I knew the dealer was just trying to take me for $1800 as it wasn't the transmission that's why I took the Jeep back from them.

I too believe that it is something electronic in the FDCM or another sensor or switch and not the actual transfer case. Especially since this is something that is being triggered on it's own. It seems like if it was the transfer case motor that was not working, then it wouldn't engage - rather something is telling the 4WLo to engage intermittently. My husband thinks perhaps its a corroded wiring connection or sensor that trips and tells the Jeep to shift at whatever speed I'm going.

We'll go ahead and disconnect the T-case control motor and see if this works. Question - since I have never in 8 years used 4WLo or 4WNeutral is it a problem to just leave this T-case motor disconnected if it's the problem?

Thanks.
Reply With Quote
  #5  
Old 01-14-2015, 06:13 PM
Frango100's Avatar
The beast from Brazil

My Jeep: 2004 4.7L WJ
 
Join Date: Dec 2009
Location: Brazil
Posts: 7,615
Thanks: 23
Thanked 424 Times in 409 Posts
Rep Power: 529936
Frango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond reputeFrango100 has a reputation beyond repute
Re: 2007 Self Shifting Into 4WLow & 4WNeutral

I would not expect a problem with the T case motor connector disconnected. Only when you would select 4Lo or N, you will get the "SERVICE 4WD" message, but since you neved used this, i would not expect a problem. Only take care, because you are not sure yet that the problem is not T case related and it could eventually switch to N or 4Lo. It is also not known if the sudden shifting to 4Lo did any damage internally. But if it doesnt make strange noises when driving, you should be ok.
__________________
Frank

JEEP Grand Cherokee 4.7 Lmtd 2004
HID 8000K in low and fog / Quad Squad member
KYB Gas-a-Just shocks / Pirelli Scorpion ATR 245/65/17 - Transgo reprogramming shiftkit.

VW Beetle 2.0 TSI 2013
My new toy
Reply With Quote
Reply

Tags
2007

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Transmission not automatically shifting into 7 and 8th gear mswlogo Trouble Shooting/Problems/Service 5 01-10-2014 08:43 AM
WJ not shifting into overdrive!! rsqweezy Troubleshooting/Problems 22 11-15-2013 05:03 AM
Car shifting into neutral randomly 14StormTrooper Trouble Shooting/Problems/Service 13 09-27-2013 04:22 PM
Hard "CLUNK" when shifting into gear HemiDawg Troubleshooting/Problems 12 08-28-2012 03:05 PM
Loud knock and jerk when shifting the transmission Into park gaidin43 Trouble Shooting/Problems/Service 8 05-26-2012 06:37 PM

» Premium Vendor Showcase
Powered by vBadvanced CMPS v3.2.3

All times are GMT -5. The time now is 02:11 AM.


Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Copyright 2012 - JeepGarage.Org
The Jeep Grand Cherokee Owners Community

JeepGarage.org is in no way associated with or endorsed by FCA US LLC. Chrysler, Dodge, Jeep, Ram, Mopar and SRT are registered trademarks of FCA US LLC.