Diagnostic Procedure

WARNING: This page is about a different car, the 2004 Nissan Murano. However, it is still accessible from the selected car via links, so may be relevant.

CHECK ECT SENSOR POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect engine coolant temperature (ECT) sensor harness connector.
3. Turn ignition switch ON.
  
  Fig 1: Disconnecting Engine Coolant Temperature Sensor Harness Connector
  Courtesy of NISSAN MOTOR CO., U.S.A.
4. Check voltage between ECT sensor terminal 1 and ground with CONSULT-II or tester.
Voltage: Approximately 5V

OK or NG
1. OK: GO TO 2.
2. NG: Repair open circuit or short to ground or short to power in harness or connectors.
  
  Fig 2: Checking Voltage Between ECT Sensor Terminal 1 And Ground
  Courtesy of NISSAN MOTOR CO., U.S.A.
CHECK EOT SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Check harness continuity between ECT sensor terminal 2 and engine ground. Refer to WIRING DIAGRAM .
  Continuity should exist.
3. Also check harness for short to power.
OK or NG
1. OK: GO TO 4.
2. NG: GO TO 3.
DETECT MALFUNCTIONING PART
Check the following.
- Joint connector-3
- Harness for open and short between ECT sensor and ECM
1. Repair open circuit or short to power in harness or connectors.
CHECK ENGINE COOLANT TEMPERATURE SENSOR
Refer to "COMPONENT INSPECTION ".

OK or NG
1. OK: GO TO 5.
2. NG: Replace engine coolant temperature sensor.
CHECK INTERMITTENT INCIDENT
Refer to "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT ".
1. :INSPECTION END