How to find out if my 2004 buick rendevous has anti lock brakes or not

The pads should have been renewed when new rotar ,s were fitted,check anti squeal plates are still on the back of pads.

wheel bearing need check

turn your key to the on position and look at the instrument panel, if you see an icon for antilock brakes, you probably have them.another way to tell is if there is wires with an electrical connector at each wheel.you might have to remove the wheels to see them.

awd disable is usually a $200 tube type sensor in the rear diff. abs light is usually front hub bearing

from what it sounds like you have a wheel bearing going bad. in GM cars and trucks they have gone to a sealed wheel bearing in the bearing is the abs sensor, if the bearing is going bad it cause that problem. I would have your wheel bearings checked.

may have a bad abs wheel speed sensor, easy way to test sensors is one at a time unplug sensor and check with ohm meter the sensor thats way off in readings is the bad one, start here first, good luck,

Probably pointing to one or more of your wheel speed sensors having problems. Have the ABS codes scanned on the vehicle. This should help give direction on where to look next. Also, check tire pressure, as uneven pressure can cause this condition.

BAD WHEE BEARING AND PROBABLY THE PLAY FROM THE WHEEL BEARING HAS DAMAGED THE SPEED SENSOR FOR THE ABS

If noise gets louder or goes away when turning or swerving (carefully) it may be a wheel bearing going.

I own the 2002 Buick Rendezvous CX and I've encountered the same problems listed here. The ABS / Traction Control Lamp stays on and was throwing a code for the left wheel speed sensor as well as an anti-lock brake code (both in the wheel bearing hub assembly). I replaced the left and right front wheel hub assembly yet this did not eliminate the abs codes. 
Ultimately, I traced this problem to a break in the wire that leads to the left hub assembly. Although the sensor was properly connected, the wire (which is encased in a plastic housing) was broken. This is the wiring which leads from the abs wiring harness under the hood down to the left wheel abs sensor. 
I would suggest that you simply remove the left wheel and inspect the wire that leads to the abs sensor (there is only one wire on each wheel). Mine literally fell apart when I removed the plastic housing around the wire. I spliced the wire together and put it back in the plastic housing. After this, my abs codes disappeared and my anti-lock brakes began working again!
This is a simple fix that many people spend $1000 + on by replacing the hub assembly which does not fix the problem.