1995 Infiniti G20 brake pedal pulsing when the car idling

[rosenrusev]

I have a 1995 G20. Recently while driving the Tach was jumping for a little while, then recently, stepped on the brakes, got a 'scraping' noise, the pedal pulsed, the speedometer stopped working, and check engine light came on. Drove home and shut off car. Restarted - brakes seem fine, check engine light is off, but speedometer is still dead. Replaced instrument cluster which fixed the tach, but speedometer still dead.

I still feel that "scraping" noise from time to time when idling on the traffic light and the pedal is pulsing.
Is that the ABS sensor, transmission or anything else?
Any suggestions?

Thank you!!!