high-pitched sound - brakes?

[gloch]

A couple of months ago, my 03 4Runner all of a sudden started making a high-pitched sound and the ABS light turned on. I assumed the brake mdule had gone bad so I finally replaced it and the sound is still there (and my wallet is lighter to the tune of $800). Any ideas as to what else it could be?

 

[SocalSam]

A couple of months ago, my 03 4Runner all of a sudden started making a high-pitched sound and the ABS light turned on. I assumed the brake mdule had gone bad so I finally replaced it and the sound is still there (and my wallet is lighter to the tune of $800). Any ideas as to what else it could be?

High-pitched sound related to speed? Engine RPM? Location? Please be more specific. And for heaven's sake, consult with us first.

 

[SocalSam]

A couple of months ago, my 03 4Runner all of a sudden started making a high-pitched sound and the ABS light turned on. I assumed the brake mdule had gone bad so I finally replaced it and the sound is still there (and my wallet is lighter to the tune of $800). Any ideas as to what else it could be?

My guess is hydroboost pump bearing. When it fails, it makes an ugly high pitch screeching sound. Pump and accumulator are common to Lexus and Prius from that era so if money is tight, that is a possible route.