Subaru LEGACY 2002 Quick Reference Index page 206

Fuel Injection (Fuel System)
F: KNOCK SENSOR
! The knock sensor is installed on the cylinder block, and senses knocking that occurs in the en-
gine.
The sensor is a piezo-electric type which converts vibration resulting from knocking into electric
!
signals.
! In addition to a piezo-electric element, the sensor has a weight and case as its components. If
knocking occurs in the engine, the weight in the case moves causing the piezo-electric element to
generate a voltage.
! The knock sensor harness is connected to the bulkhead harness.
(1) Nut
(2) Housing
(3) Piezo-electric element
(4) Resistor
(5) Weight
SENSORS AND SWITCHES
(1)
(2)
(5)
(4)
(3)
FU-26
B2H4157B