LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Infiniti >> 2017 >> QX50 AWD >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> Engine Control System (DTCS) (2 Of 4) >> DTC / Circuit Diagnosis >> DTC P0128: Thermostat Function >> Component Inspection >> Diagnostic Test
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Diagnostic Test

  1. CHECK ENGINE COOLANT TEMPERATURE SENSOR

    1. Turn ignition switch OFF.
    2. Disconnect engine coolant temperature sensor harness connector.
    3. Remove engine coolant temperature sensor. Refer to EXPLODED VIEW WITH TORQUE SPECIFICATIONS .
    4. Check resistance between engine coolant temperature sensor terminals by heating with hot water as shown in the illustration.
      G00498926Courtesy of NISSAN NORTH AMERICA, INC.
      Terminals Condition Resistance (kΩ)
      1 and 2 Temperature °C (°F) 20 (68) 2.37 - 2.63
      50 (122) 0.68 - 1.00
      90 (194) 0.236 - 0.260

    Is the inspection result normal?

    YES 

    INSPECTION END

    NO 

    Replace engine coolant temperature sensor. Refer to EXPLODED VIEW WITH TORQUE SPECIFICATIONS .