which book is this?bluegrass said:Possibly:
The anti-lock brake system consists of electronic
sensors and hydraulic solenoids controlled by a
computer. The computer has a built-in diagnostic
feature that tests the system each time you start
the engine and move the vehicle at a low speed in
forward or reverse. When the self-test occurs,
you may hear a clunk noise and/or feel a pulsation
in the brake pedal. This is normal and is not
an indication of any malfunction."
Right from the book.