you can check slector switch with ohm meter, you can check wiring to switch as below, you can check TCCM with info below, you can check PCI bus to TCCM below. If you check all this and no issues it may be a sensor or something that will require dealer support. Unfortunately some data is sent via PCI bus (that we cannot see with a standard multimeter) that tells the TCCM that is is ok to shift the transfer case - IE input / outut speed for transfer case, position sensors of transfer case, transmission shift lever position. Big problems I hear of as I was resolving my issue were TCCM transformer failures from 12V to 5V, and PCI bus connection issues from other places with speed /position information to the TCCM. Start with this, if not try subscribing to ALLDATA or similar system and see if yo can diagnose further than described below.

To all who read this forum and want to know the details of getting my 4x4 system working again - I had no lights, no 4wd.

On th selector switch I had fused power (12V) on #7, illumination on #6 (12V with headlights on) when measuring to pin #11 (ground). If you are missing the voltage on pin #1(5V) then it could be that the transfer case control module is not sending it out. The TCCM has a transformer that sounds like was going out on a lot of Dakatos / Durangos etc (I got it for $100 at salvage yard and about 4 hours of dash disassembly). The TCCM is located behind the climate control modules mounted to sheet metal dash frame by three screws, both my old and new parts are blue plastic and dimensionally a little larger that a deck of cards - about one inch thick. Very hard to see I might add. The number for a 2002 is P56028242A(F) -2003 (G) -and so on.

Once you remove all the screws in the area for dash plastic and sheet metal (and just a little force) the module comes out towards firewall without cutting anything, remove three wiring connections ("black 16 pin" "gray 16 pin" "black 4 pin") and plug in the new one.


To be sure it is the TCCM transformer check ....

1. Black 4 pin connector A -to - B which should be fused power (12V) INTO the TCCM. You should have power. If not, check fuses.

2. Black 16 pin "A1" to ground. This should show a floating voltage when the ignition is on as this is the PCI bus. ( PCI bus wires are purple ) By tramitting messages and different volumes of messages the voltage will appear to "jump" around. This indicates the TCCM hopefully is reading the PCI bus. If not, the problem may be with data going to the brain box not the box. If so continue.

3. If you want to check that your problem is the TCCM module you can verify this on the gray 12 pin connector. Pins "A8" (yellow and dark blue) and "B8" (yellow/light blue) to ground both should show 5V as long as Steps one and two above show power INTO TCCM and PCI bus "traffic". No 5V indicates your transformer from 12V to 5V is bad as well in the TCCM. Replace the TCCM.

This was the NV233 transfer case system with 2wd, 4hi, 4lo. The NV244 with Awd, 4hi, 4lo may be similar or may not be. I would recommend the Alldatadiy to get the schematics / diagrams for your vehicle.

( this post was edited, and reposted from "Babymore3" on another forum)
I take no credit for this information however, it was very helpful and resolved my issue.

 

ok, firs of all, welcome to the forum. now.... how about you provide some basic information such as year, engine size, etc. as well as any modifications you have made. thanks.

 

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that thing you did say was kinda dick-ish......anyways welcome to teh forum and good luck with the truck....post pic of it too....we all love pictures on here!!!!

 

( bump )

 

OK i located a TCCM from a junk yard, it was from a 2003 model because the part number ended in a "G" but i plugged it in and turned on the ignition and was happy to see the switch light up 2HI.
Started the truck and switched to 4HI and it worked also. turned the switch to 4LOW and the switch blinked until i moved it back to 4HI.
I know that the switch is working, i assume the TCCM is working.
I think i may have a bad servo motor driving the TC in to 4LO.
I'll have to dig deeper into troubleshooting and post the results.
The operators manual says the switch will blink until all criteria are satisfied to make the shift. I tried forward and backward, different speed, no speed, truck running and not running.
I think i'll have to pull the servo motor and see if it cycles out of the Transfer case, unless someone has a better idea.
UPDATE:
the motor was working, just a little rusty because the 4WLO position is not used very frequently.
I was advised to put the switch in 4lo and shift from D to N to R and back again. The controller will attempt for about 45 seconds.
If it doesn't work the first time, wait 5 minutes and try again. I did this and it worked through the rusty engagement. Now it works fine.

 

wow! these forums are awesome i needed that id code off the tccm module now i can call the scrapyard and make sure they got it before i pull my dash all apart ..thanks so much for posting, i am assuming that the tccm is plug and play i have an 02 same problem same circumstances... was that for a 4.7?

 

yes it is a 4.7
your welcome.

 

I know this thread is several years old, but I just bought a 2002 Dakota 4.7L, and am having the same issues. I followed the instruction in the post (which is fantastic and well detailed), I have the dash trim piece removed so I can see the TCCM module, but it's unclear to me how to actually remove it. It looks to be mounted to the inside of the dash behind the air vent hole. Is there some trick to removing it without continuing to take the dash apart? Any help or guidance would be much appreciated.