4WD question..

[FF.Martin91]

Hey, so my 03 Explorer has 4WD auto that I keep it in and I get it's suppose to automatically go from 2 to 4 when needed, but it randomly does it.. Like when the vehicle is at a stoplight or in park it'll switch to 4hi.. Figuring that is not normal (I bought the vehicle a few weeks ago so I wouldn't know).. Any idea what could be the issue and the fix to it?

 

[extra-medium]

Search for the brown wire mod. It essentially turns it into 2wd with a switch to cut power and when you need 4wd, flip the switch and hit 4 high and you're good to go.

 

[fordysenior]

How about the tires? These vehicles are sensitive to having tires of different types or tread depths on them.

 

[FF.Martin91]

How about the tires? These vehicles are sensitive to having tires of different types or tread depths on them.

Tires are all the same and in the same condition :/
Thinking maybe it's a bad sensor?
I also noticed it won't stay in 4hi if I manually select it. It'll stay in for about 30 seconds then switch back. Switches smoothly and works so I don't think that it's the transfer case/motor?

 

[imp]

Tires are all the same and in the same condition :/
Thinking maybe it's a bad sensor?
I also noticed it won't stay in 4hi if I manually select it. It'll stay in for about 30 seconds then switch back. Switches smoothly and works so I don't think that it's the transfer case/motor?

@FF.Martin91
First, how do you know it goes in to 4X4 HIGH when you switch it there? Does the 4X4 HIGH light illuminate? Second, how do know it switches itself OUT of 4X4 HIGH? Third, unless a wheel is spinning in say, gravel, the switching in and out of 4X4 HIGH to 4X4 AUTO is extremely smooth.

4X4 in your vehicle uses a clutch to send power to the front wheels; it is electrically-activated. What sensor might you think is bad? Switching power to front wheels by AUTO is done by checking wheel speed sensors. If one is bad, that will turn on the ABS light. Sounds to me like the 4X4 HIGH relay may be the culprit. It's mounted in a little box along with the 4X4 LOW relay, mounted on the passenger side of the front inner fender cover, towards the hood hinge. The other possibility is a failed Electronic Clutch, which could be slipping. imp

 

[FF.Martin91]

So when it's in auto and switches, the 4x4 high light blinks a bit and you can feel that there is more pull from the front end until it stops. If I push the 4x4 high button, the light will be solid for about 30 seconds then blink for a few more seconds, then stop. Maybe it's not the sensor, I was just trying to think of things that it might be, but don't know much about this vehicle at all.. Or any really :/

Edit: So I took the relays out, cleaned them, and put them back in.. SO FAR it seems to have solved the problem.. Haven't driven it around to test, but with the vehicle in park, it seemed to have switched and locked.. We'll see how it works and I'll post an update after I take a drive. Hopefully that will be it.

 

[imp]

So when it's in auto and switches, the 4x4 high light blinks a bit and you can feel that there is more pull from the front end until it stops. If I push the 4x4 high button, the light will be solid for about 30 seconds then blink for a few more seconds, then stop. Maybe it's not the sensor, I was just trying to think of things that it might be, but don't know much about this vehicle at all.. Or any really :/

Edit: So I took the relays out, cleaned them, and put them back in.. SO FAR it seems to have solved the problem.. Haven't driven it around to test, but with the vehicle in park, it seemed to have switched and locked.. We'll see how it works and I'll post an update after I take a drive. Hopefully that will be it.

@FF.Martin91
Glad if I helped! What did you do to clean the relays? They are identical, so switching them would prove out the HIGH relay was the culprit, since LOW will only engage with specific conditions met: in Neutral, plus brake pedal applied. imp

 

[FF.Martin91]

I used a little rubbing alcohol.. It worked at first, but then went right back to it.

 

[imp]

I used a little rubbing alcohol.. It worked at first, but then went right back to it.

@FF.Martin91
You applied this to the relay's contact lugs? Some may have seeped inside, as the relays are enclosed plastic moldings, not serviceable internally. They are quite inexpensive. I would simply buy a new one. If yer adventurous, a number of other relays are present, which could be temporarily pulled and substituted for the 4X4 HIGH relay. Those are #55, Blower Motor Relay, #56, Starter Relay, and #57, PCM Relay. Only 55 would be advisable to mess with, IMO. imp

 

[FF.Martin91]

Yeah, I applied them with a q-tip to the lugs.. I had gone to walmart and bought some, but didn't resolve the issue.. Think it could maybe be the 4x4 module relay under the dash?

 

[imp]

Yeah, I applied them with a q-tip to the lugs.. I had gone to walmart and bought some, but didn't resolve the issue.. Think it could maybe be the 4x4 module relay under the dash?

@FF.Martin91
I am not familiar with the 2003s, but my 2004 has no 4X4 module at all; the entire job is performed by the PCM. imp

 

[FF.Martin91]

So I spent all Saturday morning driving in nothing but 4x4 high (manually selected) and then switched from 4x4 high to 4x4 auto several times back to back and since then, the issue seems to be gone and works as it should. Not sure how that would have cured it, but it did (so far)!

 

[imp]

So I spent all Saturday morning driving in nothing but 4x4 high (manually selected) and then switched from 4x4 high to 4x4 auto several times back to back and since then, the issue seems to be gone and works as it should. Not sure how that would have cured it, but it did (so far)!

@FF.Martin91
Assume you were doing this switching back and forth off-pavement? If you were on pavement, then clearly the Electronic Clutch is not functioning. imp

 

[FF.Martin91]

It was on pavement. All issues were on pavement as well. I just don't get why doing that seems to have worked the kinks out

 

[imp]

It was on pavement. All issues were on pavement as well. I just don't get why doing that seems to have worked the kinks out

@FF.Martin91
A functioning Electronic Clutch will lock-up the wheels on pavement due to unequal wheel speeds, skid and screech the tires, and possibly damage the driveline. imp