Diagnostic Procedure

1. Turn ignition switch OFF.
2. Loosen and retighten two ground screws.
   Fig 1: Locating Two Engine Ground Screws & Connectors

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

   Refer to GROUND INSPECTION .

1. OK or NG 
2. OK: GO TO 2.
3. NG: Repair or replace ground connections.

1. Disconnect engine coolant temperature (ECT) sensor harness connector.
   Fig 2: Locating Engine Coolant Temp Sensor & Associated Components

   Courtesy of NISSAN MOTOR CO., U.S.A.
2. Turn ignition switch ON.
3. Check voltage between ECT sensor terminal 1 and ground with CONSULT-II or tester.

1. Voltage: Approximately 5V 
2. OK or NG 
3. OK: GO TO  4.
4. NG: GO TO 3.

Check the following.

• Harness connectors F261, F24
• Harness for open and short between ECT sensor and ECM

1. : Repair open circuit or short to ground or short to power in harness or connectors.

1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECT sensor terminal 2 and ECM terminal 89.

   For wiring diagram, refer to WIRING DIAGRAM .

   Continuity should exist. 

4. Also check harness for short to ground and short to power.

1. OK or NG 
2. OK: GO TO  6.
3. NG: GO TO 5.

Check the following.

• Harness connectors F261, F24
• Joint connector-30
• Harness for open and short between ECT sensor and ECM

1. : Repair open circuit or short to ground or short to power in harness or connectors.

Refer to COMPONENT INSPECTION .

1. OK or NG 
2. OK: GO TO 7.
3. NG: Replace engine coolant temperature sensor.

Refer to TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT .

1. : INSPECTION END