Feels like its stuck in 4wd

[Leebeejay]

I have a 2003 explorer xlt v8. When I am going slow and make sharp turns, it feels like I am in 4wd. When I go faster it is OK. No codes or lights are on. Does anyone have an idea what this could be

 

[Number Twelve]

That's a natural thing with these cars. The sharp turn causes one tire to rotate faster than another tire, so the 4WD kicks in.

 

[imp]

That's a natural thing with these cars. The sharp turn causes one tire to rotate faster than another tire, so the 4WD kicks in.

@Number Twelve
I kinda don't think so. If equipped with 4X4 AUTO, PCM is programmed to recognize that the front wheels will always be turning at unequal speeds when negotiating curves or parking, so unless a difference exists between rear axle speed and either front wheel's speed, it purposely skips turning "ON" the clutch in the Transfer Case. If equipped with Advance-Trac or Stability Control, the rear will have wheel speed sensing on both wheels, otherwise only one sensor looking at differential carrier (and thus, axle) speed. The key here is that front wheels are "free-wheeling" in 4X4 AUTO until a rear wheel, either one or both, suddenly changes speed, as in wheel spin on gravel or slick surface. It is not a natural thing, but of course a faulty rear wheel speed sensor might give erroneous data, which might cause the front wheels to be driven, but then when driving straight ahead, PCM would recognize the failed speed sensor, and begin warning the driver, likely by flashing the 4X4 HIGH lamp, and setting an appropriate code. imp

 

[doug625]

@Number Twelve
I kinda don't think so. If equipped with 4X4 AUTO, PCM is programmed to recognize that the front wheels will always be turning at unequal speeds when negotiating curves or parking, so unless a difference exists between rear axle speed and either front wheel's speed, it purposely skips turning "ON" the clutch in the Transfer Case. If equipped with Advance-Trac or Stability Control, the rear will have wheel speed sensing on both wheels, otherwise only one sensor looking at differential carrier (and thus, axle) speed. The key here is that front wheels are "free-wheeling" in 4X4 AUTO until a rear wheel, either one or both, suddenly changes speed, as in wheel spin on gravel or slick surface. It is not a natural thing, but of course a faulty rear wheel speed sensor might give erroneous data, which might cause the front wheels to be driven, but then when driving straight ahead, PCM would recognize the failed speed sensor, and begin warning the driver, likely by flashing the 4X4 HIGH lamp, and setting an appropriate code. imp

probably a bad 4x4 control module, it's in front of the glove box.

 

[imp]

probably a bad 4x4 control module, it's in front of the glove box.

@doug625
Don't know about the 2003, but my 2004 has no 4X4 Control Module. They incorporated it in the PCM. Maybe not yet in '03?
imp

 

[doug625]

@doug625
Don't know about the 2003, but my 2004 has no 4X4 Control Module. They incorporated it in the PCM. Maybe not yet in '03?
imp

As far as I know all 2002-2005 had a 4x4 module, the part numbers can vary even in the same model year but they all had it. One thing I noticed is if I ever had a rear tire with low air pressure it would act just like you're describing (one of the reasons) Odds are that's not your problem but it can make a difference. Are you positive you don't have that module? It's visible if you look behind the glove box.

 

[imp]

As far as I know all 2002-2005 had a 4x4 module, the part numbers can vary even in the same model year but they all had it. One thing I noticed is if I ever had a rear tire with low air pressure it would act just like you're describing (one of the reasons) Odds are that's not your problem but it can make a difference. Are you positive you don't have that module? It's visible if you look behind the glove box.

@doug625 From page 308-07-2 Ford Shop Manual, 2004 Explorer/Mountaineer: "Four Wheel Drive Systems":
"Four Wheel Drive Systems- Electronic Shift"
..........."utilizes the following components"
..........."four-wheel drive (4WD) control module (integral to the powertrain control module, [PCM] )

So, I figger it ain't separate anymore. imp

 

[Leebeejay]

The problem went away all by itself! I don't know how or why, but it's not doing it anymore.

 

[Phisherman]

Lots of posts regarding this end up being the VC on AWD, or tire related.

 

[lincolnshibuya]

if you have a 4x4 switch it to 2H instead of A4WD and see if it make a difference. A4WD is sensitive to difference in tire pressure and/or tire wear (uneven among them and it will lock up the front wheels).

if you have an AWD the viscous coupler is on it's way out.