Diagnosis Procedure

WARNING: This page is about a different car, the 2012 Nissan Pathfinder. However, it is still accessible from the selected car via links, so may be relevant.

CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body. Refer to "GROUND INSPECTION ".
Fig 1: Checking Ground Connections
Courtesy of NISSAN NORTH AMERICA, INC.

OK or NG

OK: GO TO 2.

NG: Repair or replace ground connections.
CHECK ECT SENSOR POWER SUPPLY CIRCUIT
1. Disconnect engine coolant temperature (ECT) sensor harness connector.
2. Turn ignition switch ON.
  
  Fig 2: Identifying Engine Coolant Temperature (ECT) Sensor Harness Connector And Rocker Cover
  Courtesy of NISSAN NORTH AMERICA, INC.
3. Check voltage between ECT sensor terminal 1 and ground with CONSULT or tester.
Voltage: Approximately 5V

Fig 3: Checking Voltage Between ECT Sensor Terminal 1 And Ground Using Tester
Courtesy of NISSAN NORTH AMERICA, INC.

OK or NG

OK: GO TO 3.

NG: Repair open circuit or short to ground or short to power in harness or connectors.
CHECK ECT SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECT sensor terminal 2 and ECM terminal 67. Refer to WIRING DIAGRAM .
  Continuity should exist .
4. Also check harness for short to ground and short to power.
OK or NG

OK: GO TO 4.

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

OK or NG

OK: GO TO 5.

NG: Replace engine coolant temperature sensor. Refer to "REMOVAL AND INSTALLATION ".
CHECK INTERMITTENT INCIDENT
Refer to "INTERMITTENT INCIDENT ".

>> INSPECTION END