Diagnostic Procedure

CHECK KNOCK SENSOR INPUT SIGNAL CIRCUIT-I
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check resistance between ECM terminal 61 and ground. Refer to WIRING DIAGRAM .
  NOTE: It is necessary to use an ohmmeter which can measure more than 10 MΩ.
  
  Resistance: Approximately 532 - 588kΩ [at 20°C (68°F)]
4. Also check harness for short to ground and short to power.
OK or NG

OK: GO TO 4.

NG: GO TO 2.
CHECK KNOCK SENSOR INPUT SIGNAL CIRCUIT-II
1. Disconnect knock sensor (1) harness connector.
  - Engine oil cooler (2)
2. Check harness continuity between ECM terminal 61 and knock sensor terminal 1. Refer to WIRING DIAGRAM .
  Continuity should exist.
  
  Fig 1: Identifying Knock Sensor And Engine Oil Cooler
  Courtesy of NISSAN MOTOR CO., U.S.A.
3. Also check harness for short to ground and short to power.
OK or NG

OK: GO TO 3.

NG: Repair open circuit or short to ground or short to power in harness or connectors.
CHECK KNOCK SENSOR
Refer to "COMPONENT INSPECTION ".

OK or NG

OK: GO TO 6.

NG: Replace knock sensor.
CHECK GROUND CONNECTIONS
Loosen and retighten ground screws on the body.

Refer to "GROUND INSPECTION ".

Fig 2: Identifying Body Ground Connections
Courtesy of NISSAN MOTOR CO., U.S.A.

OK or NG

OK: GO TO 5.

NG: Repair or replace ground connections.
CHECK KNOCK SENSOR SHIELD CIRCUIT FOR OPEN AND SHORT
1. Reconnect knock sensor harness connector.
2. Check harness continuity between ECM terminal 67 and knock sensor terminal 2.
  Refer to WIRING DIAGRAM .
  
  Continuity should exist
3. Also check harness for short to ground and short to power.
OK or NG

OK: GO TO 6.

NG: Repair open circuit or short to ground or short to power in harness or connectors.
CHECK INTERMITTENT INCIDENT
Refer to "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT ".

: INSPECTION END