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Home >> Nissan-Datsun >> 2004 >> Altima S, Standard >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 6 (Engine Control System - 3.5L) >> DTC P0117, P0118: ECT Sensor >> Diagnostic Procedure

Diagnostic Procedure

WARNING: This page is about a different variant/trim than selected.
  1. CHECK GROUND CONNECTIONS 
    1. Turn ignition switch OFF.
    2. Loosen and retighten two engine ground screws. Refer to "GROUND INSPECTION ".

    OK or NG

    1. OK : GO TO 2.
    2. NG : Repair or replace ground connections.
      Fig 1: Retightening Two Engine Ground Screws
      G02885312Courtesy of NISSAN MOTOR CO., U.S.A.
  2. CHECK ECT SENSOR POWER SUPPLY CIRCUIT 
    1. Disconnect engine coolant temperature (ECT) sensor harness connector.
    2. Turn ignition switch ON.
      Fig 2: Disconnecting Engine Coolant Temperature (ECT) Sensor Harness Connector
      G02885313Courtesy of NISSAN MOTOR CO., U.S.A.
    3. Check voltage between ECT sensor terminal 1 and ground with CONSULT-II or tester.

      Voltage: Approximately 5V 

    OK or NG

    1. OK : GO TO 3.
    2. NG : Repair open circuit or short to ground or short to power in harness or connectors.
      Fig 3: Checking Voltage Between ECT Sensor Terminal 1 And Ground
      G02885314Courtesy of NISSAN MOTOR CO., U.S.A.
  3. 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 58, ECT sensor 2 and TCM terminal 42. Refer to Wiring Diagram .

      Continuity should exist. 

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

    OK or NG

    1. OK : GO TO  5.
    2. NG : GO TO 4.
  4. DETECT MALFUNCTIONING PART 

    Check the following.

    • Harness for open and short between ECT sensor and ECM
    • Harness for open and short between ECT sensor and TCM
    1. : Repair open circuit or short to ground or short to power in harness or connectors.
  5. CHECK ENGINE COOLANT TEMPERATURE SENSOR 

    Refer to "COMPONENT INSPECTION ".

    OK or NG

    1. OK : GO TO 6.
    2. NG : Replace engine coolant temperature sensor.
  6. CHECK INTERMITTENT INCIDENT 

    Refer to "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT ".

    1. : INSPECTION END