01 Durango with 5.9L. I started with the switch after I had no engagement of four wheel drive. I checked the 2 wire harness to the engage motor on the transfer case and had no voltage coming from it with the vehicle running, in neutral, and the switch in 4HI/4LO. After I replaced the switch... still nothing, so I went and bought a TCCM from a salvage yard (tested while I was there), and still nothing! I have checked all fuses under the hood and the fuse compartment at the drivers door jamb (everything looks fine)... what am I missing? The only lights the switch has are the parking lights just as the other switch had. I do not know how to check the TCCM so I am guessing the original is probably good. The puzzling part is that with the engagement motor harness "unplugged" it still has no voltage when the normal operation sequences are initiated.

 

follow the wires and see what other components are in-line with the t-case setup, one of them has a loose connection(this could be a ground) or a bad piece in the wiring, unfortunately i cannot be more specific for you since i have not been through this problem myself, however here is the 02 service manual, it has the wiring diagrams in it

http://www.mediafire.com/?2cg2hgim2zz

 

Have you checked the relay?


Also if you have nothing at the harness but you have power at the switch then it could be wire from the TCCM to the T-case.

 

There is no TCCM on a 5.9L mated transmission.

IndyD

 

Have you check the LB/RD wire at the TCCM for power. That is the fuse 20amp fuse power feed to the TCCM. No power Then ck the C200 connector.

 

Well I have checked every harness as far as I could see without putting the vehicle on the lift. I was starting to lean toward the mode sensor in the engagement motor since I can just call it the fact that I've replaced everything except that and the motor. Now here is the dumb question... I did not check the relay... where is it at on the 01 Durango with the 5.9L with the NV233 tranfer case. If it does have a relay (which knowing my luck it does and if thats the culprit... at least I have alot of back up parts) I will probably kick my own a$$ for spending all this money rather than take it to the dealership.

 

Well I saw that and was going to say the same thing, however in the later years I wasn't 100% sure. Should have gone with my gut feeling.

 

Okay now I am very confused. I was told that the "blue module box" to the right of the steering column that is mounted by 3 screws behind the metal chassis wall WAS the transfer case control module. The book even states that on the NV233. Are you saying that this is NOT the TCCM? All I know is that there has to be some kind of electrical issue that is NOT throwing a "service light!" I just figured that after I have replaced the switch, TCCM module (if thats what it is), all the fuses are okay, and all harness are intact... then there is something I am missing. I am starting to ask myself if I am even performing the 4x4 engagement process correctly! Just to give an idea of how I am doing this is... start the vehicle... shift into "neutral", then switch to the proper setting of desire (HI or LO)... is this even correct? Sorry I am not trying to be negative... but damn... I think I should have kept my QX4!

 

Okay here is an update... I disconnected the battery positive and negative terminals for 30 minutes. After putting them back I started the vehicle... looked at the 4X4 switch and the "neutral" light is illuminated in green. I don't know if this means anything or not, but i did drive it about 100 feet and then shifted the transmission into "neutral" and switched to 4HI and still nothing.

 

The TCCM is used on ELECTRONICALLY controlled transmissions like that mated to all 4.7 & 5.7L engines. It is mounted near the pass side rad/fender and roughly the size of the PCM.

Your 5.9L is classic old school mechanically operated with bands, etc. No TCCM.