2002 Exp 4wd wont engage

[z1huggy]

Hi,
My dads 2002 Explorer with control track I think (its got a button for auto4x4, 4x4 hi, 4x4 lo) failed miserably in its first snow debut.

Selecting any of the 4x4 buttons on the dash gives you zip. I watched as my dad tried backing outta the driveway with only the rear wheels spinning. Thinking he didn't put in 4wd I was kinda chuckling at why he would try in 2wd with all this snow. As it turns out pushing the buttons for any mode of 4wd doesn't do squat. No lights on the dash, no light on the button, no sound from the t-case. nada.

I dont believe the truck has ever been in 4wd so a big thanks to the guys at the Explorer truck plant!

Any clues on what to check before he takes it to the dealer? I'm figuiring theres prolly a fuse, anything else?

Thanks

 

[lonestar]

try to SEARCH. I'm not sure, but 4X4 probs have been talked about all over this forum.

Since your getting nothing, it may be a fuse or a loose connection. Maybe someone at the plant forgot to connect something.

If someone else knows more about 2002's, hopefully they will post here, but until then, I would use the search feature. Just make sure they are talkling about newer X's. The drivetrain has changed over the years. Some have auto or AWD and some don't.

 

[z1huggy]

re:

that was my first thought but most of the posts deal with older Expy 4wd probs and search didn't uncover any with symptoms like these. Mainly no indictations of the 4wd even trying to work, no sounds, no 4wd lights etc.
Hoping someone with a 2002 may have experienced something similar.

 

[MrShorty]

Even if it wouldn't "shift" into 4x4, as I understand it, there isn't a true 2x4 option on the newer (post '97 I believe) control trac. Even in auto 4x4, it should try to spin the front when it detects slippage at the rear. Try searching for control trac. There have been a few posts that describe how the system is supposed to work. That may give you some place to start diagnosing.

 

[z1huggy]

In someones post they mentioned that up to 98-2001 it wasnt really 2x4 but since I watched the rears spin with the front tires not turning it either has a serious transfer case prob or it is indeed 2x4 with selectable auto 4x4 or 4wd. I'm wondering if it has changed since there are buttons for auto 4x4-4wd hi-4wd lo. No need for a button for auto if it was always auto 4wd.

Either way I'll know tomorrow, my dad went to the dealer today and raised hell so they are going to look at it in the morning tomorrow. They would've looked at it today if he wanted to wait.

 

[TPLYNCH]

To get into 4x4 Lo, you have to have the transmission in Neutral and your foot on the brake. Did your dad try that?

 

[z1huggy]

according to the dealer there is a circuit board in the rear of the truck that controls the 4wd activation that was inoperative.

 

[lonestar]

What do they mean by "inoperative".
For a circuit board, either it's fried or it's not pluged in..

 

[TPLYNCH]

Ok. The relay was bad. That's in the rear and you should hear a click from it when you shift into 4x4 Hi and Lo