Toyota 2VZ-FE Manual page 310

INSPECTION PROCEDURE
Check continuity between terminal KNK of ECU connector and
body ground.
Check knock sensor.
Check for short circuit between ECU and knock sensor.
Check for open circuit between ECU and knock sensor.
Does malfunction disappear when a known good knock sensor is
installed?
Replace ECU. *
ENGINE TROUBLESHOOTING – Circuit Inspection
Disconnect ECU connector.
Check continuity between terminal KNK of ECU
connector and boy ground.
Open
Go to step [ 3 ].
Disconnect knock sensor connector.
Check continuity between knock sensor terminal
and body.
Open
Replace knock sensor.
Repair or replace harness or connector.
Replace knock sensor.
* When diag. code 52 is not displayed, proceed to
next circuit inspection shown on matrix chart
(See page TR–21).
TR–73