Knock Sensor

Use an ohmmeter which can measure more than 10 MΩ.

Disconnect knock sensor harness connector.
Check resistance between terminal 1 and ground.
Resistance: 530 - 590 kΩ [at 20°C (68°F)]

Fig 1: Checking Resistance Between Knock Sensor Terminal 1 & Ground

Courtesy of NISSAN MOTOR CO., U.S.A.

CAUTION: Discard any knock sensors that have been dropped or physically damaged. Use only new ones.