Hello everyone. First off, I'd like to send a HUGE THANK YOU to everyone that has posted on this thread. I was ready to pull my hair out over the issues I was having with my Explorer, especially since it's the holidays and money is tight. I didn't know how much I'd have to spend just to have someone LOOK at my problem, let alone fix it. To pay it forward, I decided to post my experience. It is a tad different than everyone else's, but still with the same root cause and fix.
My 2002 Explorer is actually my wife's truck. A few weeks ago, she came in after just leaving and asked me to take a look at her truck, that it was lurching as she turned out of the driveway. As soon as I started it up, I noticed that the 4x4 low light was on. I attempted to place it in auto, to no avail. The light on the selector button would just blink. I slowly got it back in our driveway, and finally got it to go into auto. After driving it a little, I decided she must have accidentally engaged it (wasn't sure at the time how, since it needs to be in N).
About a week later, it happened again. Somehow 4x4 low was engaging by itself when the car was started. I went out to check it out and sure enough, when I turned the car on the 4x4 high and low idiot lights blinked a few times and the low light was illuminated on the low button. This time, I could NOT get it out of low right away. The light would flash on the button, but I wouldn't hear the clicking from the CM box or anything. By that time, I had found this thread about the issue, so I tried disconnecting the battery, disconnecting the CM and connecting both again. This temporarily got it back in auto. I later found that just disconnecting the battery and reconnecting after a minute or two would do the trick. You don't have to mess with the CM if you are just trying to get it back in auto.
Two days later, it went back into low by itself. Looking back, I do believe the three times it happened were cold mornings, not sure if that was related. Anyways, you can't let your wife drive a car around that engages itself in 4x4 low if you don't think you can explain to her how to get it off. Doing some research and asking the Silver State Ford parts guy his opinion, I decided to disconnect the 4x4 control module and see if I could drive it strictly in 4 auto (ultimately, 2 wheel drive).
I was able to drive normally without the 4x4 CM connected. (You have to make sure it's in 4 auto before disconnecting it. The first time I did this, I didn't get it back into 4 auto before disconnecting it, so when I drove with the CM disconnected, it drove horribly, since it was in 4 low still.) I'm not officially telling you that you won't hurt your car driving it with the CM connected at all, but I did it multiple times for about a week with no isssues. I also noticed someone else say that they drove like this for a while with no issues. So if you need to drive and you are willing to risk it, try it out.
I was hesitant to buy the new CM at first, since I was doing some self-diagnosing. However, since it worked fine when I disconnected it totally, I decided that was proof enough for me. I can validate what everyone is saying about silver state ford. They have GREAT customer service. I ordered the part at 2:30 PM EST on a Thursday and the part arrived Saturday morning, and I just used their standard shipping. The part is $165 and they charge someting like 12% for shipping, so the total was $185. A lot better than the $311 the dealer wanted! Here is the website one more time:
http://www.silverstatefordparts.com/partlocator/index.cfm?siteid=214290
I would still recommend calling their number (1-800-810-6596) just to verify the part number. Then just enter the part number on that page and order it. My part was 2c5z7e453a.
As soon as I received the part, I put it in. Only took me 10 minute to disconnect the neg battery terminal, undo the glove compartment, and install the new part, and redo everything. I already had the old one out since I had disconnected it days earlier. It has worked like a champ since then. I cycled through all 4x4 modes with no issues and it's driving fine. Granted, it's only been a couple of days. If something does go wrong, you can be sure I'll be back on this forum letting you know.
I do want to mention that I NEVER had this shift into low while I was driving. It only happened when we started the car. If I would have had it happen while going 30 MPH, who knows what would have happened to the transmission! If someone does have that issue, I wouldn't waste time trying to diagnose it yourself.
Again, thanks to everyone that has posted on this thread. I don't have a need to check back on this thread anymore, but I'll try to remember to every once in a while in case someone had a specific question for me. Good luck and Merry Christmas!