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post #1 of 6 Old 08-17-2019, 05:45 PM Thread Starter
DRB1971
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Exclamation Serve 4wd

This is the story:
2012 GC limited 3.6l. 121k
Purchased used 112k 07/18

Drove about 350 miles round trip with a twelve hour break in the middle. While on break drove about 15 miles in heavy heavy stop and go traffic, parked truck for another 6 hours. Drove about 30 miles at high way speed, stopped for dinner, got back in truck and drove the 150 give/take home. Got home unloaded, drove another 20 miles round trip and parked truck for the night.

When wife went to leave about twelve hours later, started truck, immediately had serve 4WD light and all other lights to go with. Truck backed out fine, put in drive, now seems like in limp mode first gear. Have done all the obd scans, no check engine light, scanner says ďlost communication with four-wheel drive clutch control moduleĒ

Have gravel drive and only rear wheels have power to them. All lights in selector are off, no 4lo.

Please any help!

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post #2 of 6 Old 08-17-2019, 07:27 PM
ColdCase
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You may need a more capable scanner to read the codes, but what exactly is the fault code? There are quite a few service 4WD threads, and its not that simple. Lots of oportunities.

Given that one of the modules says it lost communication with control module, I'd suspect perhaps wiring/lose connection but more likely a control module failed. There is a transfer case/drivetrain control module and transmission control module, the select terrain switch and instument cluster involved in one way or another.

If you replace the transfer case control module you want to replace the transfer case actuator too as a fault in one often burns out the other. Some here have had to replace the transfer case to resolve similar issues.

But you say the transmission may be in limp mode... so the transmission control module could be the one that that failed... which may also light up the service 4WD indicator, I think.

On a V6 of that era the TCM is mounted under the center dash panel, the drivetrain control module (AKA transfer case control module) is located in the compartment under the driver's seat.

Then is also could be something messing with the CAN-C bus. just saying, it may not be that simple.

Some people think I'm stupid and I totally disagree. But my biggest fear is that me thinking I'm smart proves them right.....
Current: 2011 Grand Cherokee Overland V8, 2009 Liberty Rocky Mt V6
Previous: 2000 Grand Cherokee Laredo I6, 1979 CJ7 I6 Quadratrac
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post #3 of 6 Old 08-17-2019, 07:40 PM Thread Starter
DRB1971
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Thanks, Cold Case. You already gave me some info I had been searching for. Basically where those modules are located.
The Code is: U0114
I think this code is thrown for a couple different things. I have tried every trick or have read about.
I miss my TJ.
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post #4 of 6 Old 08-17-2019, 11:12 PM
ColdCase
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Is the IOD fuse blown? Is the battery original? U0114-00 can be set by two or three different modules. If its set by several, then its a good chance the transfer case control module is dead.

https://www.obd2-code.com/2017/06/u0...-sway-bar.html or https://s3.amazonaws.com/jeepwrangle.../7c038ff6.html

When reading those references, remember that the WK2 FDCM is known as the transfer case or driveline control module. There is no auto sway bar in a WK2. The V6 WK2 limited won't have dif solenoids. On other models there is a separate ELSD module.

So the transfer case control module is probably dead, maybe also the transfer case actuator. Seems to be a fairly common problem. If you want to throw parts at it, start there. Replace them both because the actuator can burn out the control module. There have been several threads here on the subject. Otherwise you can go through and wiggle wires and reseat connectors or take it to a shop.

Some people think I'm stupid and I totally disagree. But my biggest fear is that me thinking I'm smart proves them right.....
Current: 2011 Grand Cherokee Overland V8, 2009 Liberty Rocky Mt V6
Previous: 2000 Grand Cherokee Laredo I6, 1979 CJ7 I6 Quadratrac
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post #5 of 6 Old 08-18-2019, 09:41 AM Thread Starter
DRB1971
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Cold Case,

I exhaustively dug through threads last night. Until you told me where the transfer case module was I was at a loss. I couldnít find it in Haynes or chiton, all showed under rear seat. You tube showed under rear seat. I had opened that compartment up and saw the module, but wasnít 100%.

So, I did a conglomeration of the ideas I had read. Used scanner, disconnected battery, etc...
I unplugged the FDMC, drove the truck to the end of the drive, backed the truck back up...did this twice.
Shut the car off, plugged the FDMC back in, hopped in, pushed the start button, with in seconds the serve 4wd light off, truck out of limp mode and all gears and select trac worked. Did not try 4lo because, as I said at beginning, wifeís Jeep and I donít feel she will need 4lo at Harris Teeter parking lot..lol. Like I said, I miss my TJ.

Considering trading this in for a 2016 with 28k...have some of these bugs been worked out?
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post #6 of 6 Old 08-18-2019, 12:11 PM
ColdCase
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I suspect there was a bad connection in the module connector (pushed pin perhaps). Disconnecting would cause it to re-boot, however. But thats the same as turning off the Jeep or disconnecting the battery.

Don't think its a bug, but a problem/failure of some sort and that would not likely change from model year to model year. They did revamp the data bus in 2014 or so. There are mixed feelings whether that caused or fixed problems, just different failures.

Some people think I'm stupid and I totally disagree. But my biggest fear is that me thinking I'm smart proves them right.....
Current: 2011 Grand Cherokee Overland V8, 2009 Liberty Rocky Mt V6
Previous: 2000 Grand Cherokee Laredo I6, 1979 CJ7 I6 Quadratrac
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