Stuck in 4x4

[jhartney]

My situation is I believe that my 02 Explorer is stuck in 4x4 High. With vehicle raised and in Drive, both rear tires rotate and one front tire rotates, I can stop the one front tire and the other tire will begin to rotate. Highway driving sounds like transfer case is engaged. Low speed turns has that jumping/grinding thing one notices when in 4x4. Local trany shop also says it is in 4x4. I push the 4x4 Auto button, light is OFF, push the 4x4 High and High light is ON, but notice NO mechanical differences. 4x4 Low seems to engage/disengage and work correctly.

I have seen other posts about adding friction modifiers to the differential and replacing the Powertrain Control Module. However all the posts on the PCM state the dash lights dont work and mine do. Also all posts state they are in 2WD where I believe I am stuck in 4WD.

Any suggestion on where I should start with diagnosing my repair? The trany shop says his diag reports the PCM being bad but his inutition tells him otherwise, he also said the PCM is $500 where other posts suggest $150.

Thnaks
JON

 

[jhartney]

1/2" to 3/4" drive adapter - $3
self primming hand pump - $6
2 bottles of oil and one tube of additive - $15
Saving $$$$ from NOT going to a dealership - - - PRICELESS

 

[hitman17mk]

read up ony your explorer, its is in 4x4 all the time, any explorer i think after 98 unless only a 2wd explorer is ALWAYS in 4wheel drive. hint 4x4 auto, what happens is it gives 80% torque to the rear and 20 to the front, when the rear wheels slip it put more torque to the front, 4x4 high Locks the center diff giving 50/50 all the time. and 4x4 low is well 4x4 low i think it something liek 2.43:1? but ur truck is always in 4x4 so if its having problems, thats not it.