Whinning noise from front of vehicle

I would have to say that your front wheel bearings are no good and need replacing that is the usual sound they make and the pitch changes threw out the driving speeds and corners I would say.

Sounds like the wheel bearing..Jack up the vehicl and move the wheel up and down..There should be no movement

you can check for any play in the bearing up/down or side to side
you can also rotate the tire & see if the noise follows the tire

does it get louder above 45-60mph? and much quieter at low speeds. It could be wheel bearings, a rear differential or front differential. If its a grinding humming noise its wheel bearings, listenin to see if theyre coming from the front or rear, left or right, or both when your driving to know what wheel bearing are bad. If its a whinning noise, its probably a differential. check and listen to hear if its coming from the front or rear. Also, check for loose plastic around the wheels. Lastly check your tires for uneven or choppy wear. move your hands front to back on the top of the tire. does it feel really choppy and rough, maybe you just need new tires

check outer cv joint & wheel bearings

Sounds like you have a bad bearing hub (likely in front but you need to determine which side) You really can't tell by shaking it, unless its falling apart. Remove front brakes and rotors and turn the bearing by hand, any slight roughness is a problem (you can't exert as much force as the vehicle weight of the vehicle)

the trailblazers are designed to shift from 2 wheel to AWD on the fly. BUT NOT TO EITHER OF THE 4 WHEEL OPTIONS. I'd suggest you get it to a mechanic to evaluate the damages.
Jer

I had the same problem on my 2005 Envoy. Turned out to be the idler pulley bearing. It is just a pulley the belt rides on. The bearing in the pulley was what was making the high pitched whine. I replaced the bearing, and the noise went away.

When the ABS light is on when driving there is a problem in the anti lock brake system and you will need to have it tested to find out what the problem is. As long as the light is on the ABS has been shut off by the computer until it is repaired. There could be problems with one of the wheel speed sensors, wiring or the ABS pump. On some vehicles the red brake light will come on too.

front hubs need replaceing or greased. maybe front dif needs fluid.