Diagnostic Procedure

1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check resistance between ECM terminal 15 and engine 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 

1. OK: GO TO  4.
2. NG: GO TO 2.

1. Disconnect knock sensor harness connector.
2. Check harness continuity between ECM terminal 15 and knock sensor terminal 1.

   Refer to WIRING DIAGRAM .

   Continuity should exist. 

   Fig 1: Checking Knock Sensor Input Signal Circuit For Open And Short-II

   Courtesy of NISSAN MOTOR CO., U.S.A.
3. Also check harness for short to ground and short to power.

OK or NG 

1. OK: GO TO  4.
2. NG: GO TO 3.

Check the following.

• Harness connectors F9, F241
• Harness for open or short between ECM and knock sensor
  1. Repair open circuit or short to ground or short to power in harness or connectors.

Refer to "COMPONENT INSPECTION ".

OK or NG 

1. OK: GO TO 5.
2. NG: Replace knock sensor.

Loosen and retighten engine ground screws.

1. GO TO 6.
   Fig 2: Tightening Engine Ground Screws

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

1. Turn ignition switch OFF.
2. Disconnect knock sensor harness connector.
3. Check harness continuity between knock sensor terminal 2 and engine ground. Refer to WIRING DIAGRAM .

   Continuity should exist. 

OK or NG 

1. OK: GO TO  8.
2. NG: GO TO 7.

Check the following.

• Harness connectors F9, F241
• Harness connectors F102, M82
• Harness for open or short between knock sensor terminal 2 and engine ground
  1. Repair open circuit or short power in harness or connectors.

Refer to "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT ".

1. INSPECTION END