Diagnostic Procedure

1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body. See Figure .

   Refer to GROUND INSPECTION  .

OK or NG

1. OK: go to  2 .
2. NG: Repair or replace ground connections.

1. Disconnect engine COOLANT temperature (ECT) sensor harness connector.
   Fig 1: Disconnecting Engine COOLANT Temperature (ECT) Sensor Harness Connector

   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 

OK or NG

1. OK: go to  4 .
2. NG: go to  3 .
   Fig 2: Checking Voltage Between ECT Sensor Terminal 1 & Ground (W/DVOM)

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

Check the following.

• Harness connector F261, F24
• Harness for open or short between ECM and engine COOLANT temperature sensor
  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 67.

   Refer to wiring diagram. See Figure .

   1. Continuity should exist  .
4. Also check harness for short to ground and short to power.

OK or NG

1. OK: go to  6 .
2. NG: go to  5 .

Check the following.

• Harness connector 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.

Refer to COMPONENT INSPECTION  .

OK or NG

1. OK: go to  7 .
2. NG: Replace engine COOLANT temperature sensor.

Refer to TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT  .

1. Inspection end