My Explorer has started to engage its 4 wheel drive almost all the time, regardless of conditions - at least that's what it sounds/feels like. Also, the 4wd and 4wdLow lights are flashing. Anything I can do before I take it in?

Thanks,
Mike

Check tire pressures.
Uneven pressure will change the rotation
differential, and fool the computer into
engageing the 4x
Try 32lbs in each tire.
Old aluminium rims tend to carode , and slow leak.

Just like Saperich says... check that air pressure!

Also 1 bald tire or sometimes different manufactured tires have different diameters also.

Maybe a speed sensor also. Might have to pull the codes if the tires check OK. These really like to actually eat up the aluminum case halfs of the transfercase too. :(

Yes - I was wondering if it might be the speed sensors - any way for me to check them myself?

Also - what eats up the aluminum case?

I'll definitely check the tires - would uneven tire pressure make the 4WD lights flash?

Earlier today it was doing it all the time - but I just drove the vehicle about 20 miles, and it didn't do it once.

MBD

Just like Saperich says... check that air pressure!

Also 1 bald tire or sometimes different manufactured tires have different diameters also.

Maybe a speed sensor also. Might have to pull the codes if the tires check OK. These really like to actually eat up the aluminum case halfs of the transfercase too. :(

You'll need a scanner to see some speed sensor operation. And sometimes you get codes off the module under side panel behind left rear door. It should not be too hard to figure out with a data reading scan tool. Not just a code reader. Most likely it would be best to hand it over to a reputable shop for diagnostics. Unless you want to invest in scan tools, wiring diagrams and tech service. $$$ The case wears from poor design and normal wear for the most part. Good luck