Diagnostic Procedure

CHECK KNOCK SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT-I
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check resistance between ECM terminal 15 and ground. Refer to Wiring Diagram.
  NOTE: It is necessary to use an ohmmeter which can measure more than 10 MΩ
  
  Resistance: Approximately 532 - 588 kΩ [at 20°C (68°F)]
4. Also check harness for short to ground and short to power.
OK or NG

OK: GO TO 5.

NG: GO TO 2.
CHECK KNOCK SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT-II
1. Disconnect knock sensor harness connector.
  
  Fig 1: Identifying Knock Sensor
  Courtesy of NISSAN MOTOR CO., U.S.A.
2. Check harness continuity between ECM terminal 15 and knock sensor terminal 1.
  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 4.

NG: GO TO 3.
DETECT MALFUNCTIONING PART
Check the following.
- Harness connectors F26, F301
- Harness for open or short between ECM and knock sensor
CHECK KNOCK SENSOR
Refer to "COMPONENT INSPECTION ."

OK or NG

OK: GO TO 5.

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

Refer to "GROUND INSPECTION ."

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

OK or NG

OK: GO TO 6.

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

OK: GO TO 8.

NG: GO TO 7.
DETECT MALFUNCTIONING PART
Check the following.
- Harness connectors F26, F301
- Harness connectors F58, M70
- Harness for open or short between knock sensor and ground
CHECK INTERMITTENT INCIDENT
Refer to "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT ."

>> INSPECTION END