98 Explorer Sport stuck in 4 wheel drive

Any ideas on how to get my explorer sport out of 4 wheel drive? i know very little about vehicles. the 4 wheel high and low lights work when i turn switch to engage and off when i disengage but it stays in 4 wheel drive. maybe something is stuck? i don't think it is electrical. anything would be appreciated. thanks

Stuck in 4wd Low? You need to shift the trans into N and come to a stop before shifting into or out of 4wd Low.

If it is stuck on in 4wd High, it is almost definitely a problem with the electronics, because the difference between 4wd Auto and 4wd High is just the amount of time that the transfer case clutch is engaged (only when needed in 4wd Auto vs. more of the time in 4wd High).

How can you tell it's stuck in 4wd?

There's a few things to check: Power from teh TOD relay, power from the TCS relay, both leading to the brown wire. The simplest way to isolate the electronics is to unplug the transfer case connector, and take it for a drive. Your 4x4 lights will start flashing, but that's OK.... If the vehicle still acts like it's in 4wd with the t-case unplugged, you have a mechanical problem with the case itself. If unplugging it fixes the problem, you have electrical gremlins and we can go from there.

Let us know what you find.

-Joe

my gas mileage really decreased and then checked it out when it snowed. it's been like this for several months now. i only drive about two miles to work so i haven't put many miles on it. is there an auto 4wd that i don't know about that would cause front tires to work in snow or rain? i am pretty sure i feel it pulling in front when roads are wet too. i do know one thing though that i used to get about 280 miles per tank and now get 200 if i'm lucky. the 4x4 high and low lights both work properly and i have tried putting it in 4x4 low, completely stopping putting in neutral, and driving in reverse for about 25 yards. so far no luck. i will give your advice a shot. thanks

You have Control Trac 4wd on your 98 which works in 3 different modes:

Auto 4wd: This is the 'normal' driving mode. The system sends approximately 4% of the power (torque) to the front wheels, 96% to the rear. When it detects that the rear wheels are slipping (it monitors the speeds of the front and rear driveshafts to tell) then it will start to send more power to the front wheels. You do not have a 2wd option on a stock Control Trac, although it is possible to disable the front by installing a switch, search for "Brown Wire Mod" for more info on this. Front hubs and driveshaft are engaged (turn) no matter what. The power is controlled by an electronically controlled clutch inside the transfer case.

4wd High: You should only use this on slippery surfaces, snow or off road. The system sends a higher level of power to the front all of the time (but not 100% of the time).

4wd Low: The transfer case shifts into Low range. This is why you must shift to N and come to a stop. The power is split 50/50 between the front and rear wheels all of the time. Only use this off road on surfaces that "give" because you can get driveline binding during turns and damage the drivetrain.

dogfriend said:

You have Control Trac 4wd on your 98 which works in 3 different modes:

Auto 4wd: This is the 'normal' driving mode. The system sends approximately 4% of the power (torque) to the front wheels, 96% to the rear. When it detects that the rear wheels are slipping (it monitors the speeds of the front and rear driveshafts to tell) then it will start to send more power to the front wheels. You do not have a 2wd option on a stock Control Trac, although it is possible to disable the front by installing a switch, search for "Brown Wire Mod" for more info on this. Front hubs and driveshaft are engaged (turn) no matter what. The power is controlled by an electronically controlled clutch inside the transfer case.

Click to expand...

Close, but not quite...

The control trac transfer case is either engaged or disengaged. The GEM module monitors the wheel speeds, then commands the Torque On Demand relay to lock or unlock the transfer case as necessary by varying the duty cycle of the transfer case clutch. Mechanically speaking, the clutch is either engaged or disengaged, so you either get a 0/100 split or a 50/50 power split.

4wd High: You should only use this on slippery surfaces, snow or off road. The system sends a higher level of power to the front all of the time (but not 100% of the time).

Click to expand...

Again, close, but not quite. 4High simply locks the transfer case clutch coil in at 100% duty cycle. It is, in fact, a true full-time 4wd at that point.

4wd Low: The transfer case shifts into Low range. This is why you must shift to N and come to a stop. The power is split 50/50 between the front and rear wheels all of the time. Only use this off road on surfaces that "give" because you can get driveline binding during turns and damage the drivetrain.

Click to expand...

The transfer case is engaged at 100% duty cycle just like in 4high, but with the addition of the planetary reduction gearset being engaged. That's why the brown wire mod can provide 2wd low range by simply interrupting the power flow to the transfer case clutch coil.

The bottom line is that the front half of the drivetrain will, in fact, be engaged at all times. The coupling/decoupling for 4wd simply takes place inside the transfer case. The front drivetrain is live at all times.


-Joe

No, its not engaged at 100% in 4wd High. I have verified this with a scan tool for myself. The duty cycle was about 13% in 4wd High, I don't recall what it was in 4wd Auto, but it was very low (but not zero) in a non slipping condition.

The signal to the transfer clutch case isn't on or off, but is a PWM (pulse width modulated) signal from the GEM to the TOD relay to turn the clutch on and off proportional to the PWM signal.

dogfriend said:

No, its not engaged at 100% in 4wd High. I have verified this with a scan tool for myself. The duty cycle was about 13% in 4wd High, I don't recall what it was in 4wd Auto, but it was very low (but not zero) in a non slipping condition.

The signal to the transfer clutch case isn't on or off, but is a PWM (pulse width modulated) signal from the GEM to the TOD relay to turn the clutch on and off proportional to the PWM signal.

Click to expand...

If it's anything less than 100% in 4high, then how come there's a full 14V on the brown wire in 4 high, and 4 low? Were you measuring the duty cycle of the GEM or the output of the TOD relay? Are you sure that's not a voltage reading instead of a duty cycle reading?

I'd love to get my hands on a scan tool like that....

-Joe

edit: Another thought: When were you measuring the duty cycles? With the vehicle stopped, or driving down the road? This got me curious, so I just went out for a drive with the DMM hooked up to see what exactly it does.... I'll post the results in a bit...

-Joe

I have a Diagtek scan tool which can read PID's from the PCM, GEM, ABS, SRS. I don't remember the name of the PID for the transfer clutch duty cycle right now, but I can monitor it as well as the front and rear driveshaft speed sensors. The software runs on a Palm PDA. Apparently, it is no longer available, see www.diagtek.com

The reason that you see full voltage is because your voltmeter is averaging the signal. My recollection is that the PWM signal looks like a square wave with a frequency of 33 Hz (turns off and on 33 times per second). By varying the time on in each cycle, the GEM controls the amount of current sent to the transfer case clutch (and proportionally the amount of torque sent to the front driveshaft).

http://www.embedded.com/story/OEG20010821S0096

Instead of continuing to hijack this thread, I decided to continue the discussion over yonder:

http://www.explorerforum.com/forums/showthread.php?p=1422436#post1422436

Were you measuring the duty cycles while stopped, or while rolling? Any way to log the duty cycle data with wheel speed, TP, and switch mode? That would be sweet!

I have been researching this issue but haven't quite found a direct answer. I'm assuming the electronic control module must have failed but basically same issues I see everyone else had. I put my X in 4 high while on the beach but it actually got stuck in 4 low. I crawled under my X to look for this brown wire but didn't find it. Maybe I was looking in the wrong place. I took it to a mechanic and he was able to bypass something and get in 4 high but wouldn't do anything else with out charging more. So now my X is in 4 high but taking sharp turns sounds so bad and I'm sure it's gonna screw something else up. Do I just need to find this brown wire and hope it goes back into auto or am I missing something here? By the way my 98 explorer sport is a 5 speed manual, not sure if that makes any difference at all. The mechanic disabled the switch on my dash too so it does nothing now and my 4wd high and low lights will flash from time time which to my understanding means the 4wd is messed up (obviously since i'm stuck in 4 high)


Been reading up on the brown wire mod thread. Not sure that I want to "mod" the entire thing I just want to be in 2 wheel again so I don't have to hear my car binding up anymore. Also everyone is saying the switch says 4auto, 4 high and 4 low, mine just says Auto, 4High and 4Low. The mechanic tried tapping on the transfer case but it didn't free anything up. At least it looked like that's where he was tapping.

Same problem - locked in 4X4 high

98whitexploda said:

I have been researching this issue but haven't quite found a direct answer. I'm assuming the electronic control module must have failed but basically same issues I see everyone else had. I put my X in 4 high while on the beach but it actually got stuck in 4 low. I crawled under my X to look for this brown wire but didn't find it. Maybe I was looking in the wrong place. I took it to a mechanic and he was able to bypass something and get in 4 high but wouldn't do anything else with out charging more. So now my X is in 4 high but taking sharp turns sounds so bad and I'm sure it's gonna screw something else up. Do I just need to find this brown wire and hope it goes back into auto or am I missing something here? By the way my 98 explorer sport is a 5 speed manual, not sure if that makes any difference at all. The mechanic disabled the switch on my dash too so it does nothing now and my 4wd high and low lights will flash from time time which to my understanding means the 4wd is messed up (obviously since i'm stuck in 4 high)


Been reading up on the brown wire mod thread. Not sure that I want to "mod" the entire thing I just want to be in 2 wheel again so I don't have to hear my car binding up anymore. Also everyone is saying the switch says 4auto, 4 high and 4 low, mine just says Auto, 4High and 4Low. The mechanic tried tapping on the transfer case but it didn't free anything up. At least it looked like that's where he was tapping.

Click to expand...

Has anyone found a resolution to this problem? I too was told to bang on the shift motor (lightly) but not the transfer case. It does not seem useful to unplug the shift motor let alone do the brown wire mod if the transfer case is still stuck in 4X4 high. There has to be a way to unlock it manually? No? I'm replacing the shift motor this weekend, so when I get the old one off, is there something I can do then to manually unlock it? Right now, I just took the front drive shaft off and no more binding in the front end. However I do need 4X4 for the Winter! I'm a newbie here and to Explorers. I just bought the Explorer 2 weeks ago. It got locked in 4X4 on my first off road jaunt to test the 4X4. Of course, it worked fine when I test drove it. Thanks in advance to anyone who can help me out or point me in the right direction.

ExloringXLT said:

Has anyone found a resolution to this problem? I too was told to bang on the shift motor (lightly) but not the transfer case. It does not seem useful to unplug the shift motor let alone do the brown wire mod if the transfer case is still stuck in 4X4 high. There has to be a way to unlock it manually? No? I'm replacing the shift motor this weekend, so when I get the old one off, is there something I can do then to manually unlock it? Right now, I just took the front drive shaft off and no more binding in the front end. However I do need 4X4 for the Winter! I'm a newbie here and to Explorers. I just bought the Explorer 2 weeks ago. It got locked in 4X4 on my first off road jaunt to test the 4X4. Of course, it worked fine when I test drove it. Thanks in advance to anyone who can help me out or point me in the right direction.

Click to expand...

First we must isolate issue to mechanical or electrical. Unplug the 16 pin connector at at the transfer case and go a ride. That will cut the power power the transfer transfer clutch coil. If the binding is gone, you have an electronics issue track down. If it it still binds, you have a mechanical in the case. Good luck!

gijoecam said:

First we must isolate issue to mechanical or electrical. Unplug the 16 pin connector at at the transfer case and go a ride. That will cut the power power the transfer transfer clutch coil. If the binding is gone, you have an electronics issue track down. If it it still binds, you have a mechanical in the case. Good luck!

Click to expand...

Hi Joe - The first thing I tried was to unplug the 16 pin connector, drove it, and it was still binding up front. A ford mechanic said to tap lightly on the shift motor to unlock the 4X4 engagement, but that too did nothing. Since the shift motor is electrical, do you think that replacing that will also be fruitless? I have it stuck in my head I can somehow manually turn the transfer case out of 4X4? Not sure if my truck model is showing - 1999 Ford Exporer XLT V6 4.0 Automatic tranny. Thanks - Mike

Ok so I've experienced this same issue on 4 of my 5 different explorers I've owned. A very quick and simple temporary fix is to make sure the switch is in either 2hi or auto position... look for all the fuses in both fuse panels that pertain to the 4x4 system. Remove all of those and cycle the key on-off a couple times then turn the key off. Reinsert the fuses in their proper locations then start the engine. This should get you back in 2hi again until you use the 4hi or 4 low positions again. Then you will have to repeat this process.
The reason for this is inside the electric shift motor. There are copper contacts that the controls use to sense what position the motor is in. Once these contacts begin to tarnish or corrode the controls get "confused" and can no longer tell what position the motor is in and locks out the ability to change its position. When the fuse pulling and keyon-off happens it basically resets and returns the shift motor to the 2hi position. Hopefully this will work for you as it has for me on many a trail trip four-wheeling during my many adventures while in the military. Also...never assume that a stock explorer cannot win some serious money in off-road bets. I won well over $2500 over six months while stationed in Charleston,SC and in Groton, CT. Ha ha. They will suprise you.
The only true fix for this problem is to remove the shift motor and attempt to disassemble and clean the contacts yourself...or buy yourself a new shift motor with a lifetime warranty because it will happen again. There is no way to make them water/element proof.

More information about this shift motor issue can be found in the "tech library" section of therangerstation.com 's site under transfer case troubleshooting. Hopefully I didn't step on anyone's toes with that.

One more thing...if you are up to it you can manually shift the transfer case to 2hi. Crawl under the x and unbolt the shift motor. Find a scrap large blade flat-head screwdriver and a good strong jaw pair of channel locks or visegrips. Gently tap the screwdriver into the triangle shaped hole on the back of the transfer case that the shaft of the motor inserts into. Turn the screwdriver (I believe i remember to be) counter clock wise with the visegrips or channel-lock pliers until it stops...don't force it too hard.

I would highly recommend the fuse pulling method I listed above or ultimately purchasing a new transfer case shift motor over this, as its extremely hard to tell what position the transfer case is in on the electric shift models and I do NOT recommend manually shifting these unless it is a absolute emergency/necessity. You are on your own now as that is all i know about this matter.

Hi Gasman - I did take off the shift motor and to my surprise the shaft was pointing to L while my X is acting like 4H. For instance, I can do 70 MPH on the freeway at only 2,200 RPMs. So it is either releasing somewhere, some time, but still always binds up front during slow turns.

I was also able to turn the shaft easily by hand which causes concern. I do have a new shift motor but everything seems to be pointing now to a mechanical issue inside the transfer case.

Wouldn't disconnecting the connector between the xfer case and shift motor in effect do the same thing as pulling all the fuses and trying to reset it, or no?

Thanks...

In that case it sounds as if you are having an issue with your vacuum pulse hubs or the electrical /or leaking vacuum lines to the switch for the vacuum to your hubs or feeding to the hubs themselves. On higher mileage vehicles the hubs can be neglected and usually were never serviced by removing them and cleaning the old grease out and regreasing them. Your best bet is to go to a local autoparts store and buy a repair manual for your explorer(haynes tends to offer better diagrams and descriptions tha chiltons). The manual should explain how to service your hubs.

The free moving transfer case is not a concern as mine was usually in a bind when I had to turn it. I have had one of my former explorers that the hubs had dried up grease and dry-rotted vacuum lines feeding to the back side of the front hubs. I was able to replace the vacuum line withh regular size-matched hose and then removed the hub...which is a pain the first go around...cleaned and greased them and never had any more issues out of them. They are plastic so be careful not to damage them.
Pulling the connector on the side of the transfer case only removes power to the motor itself. By removing the fuses it removes power to the controls as well. I tried the connector several times but to no avail. The first time I removed the fuses it reset and did over twenty more times until I replaced the shift motor. Every v-6 model I owned had the same issue around 90,000 miles. It always happened on the worst parts of the trails.

Try checking the vacuum lines first and then inside the plastic hub to see what kind of shape the grease is in. It takes three hands and three-four screw drivers and several choice words to lift the tabs so you can remove the hubs.

Thanks gas man - since I have the front drive line off now - which eliminates all binding up front, does that mean the hubs are OK?