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HOMESERVICE MANUALSINFINITI2019Q70 3.7 LUXE, AWDREPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT VARIANT/TRIMSECTION 2 (ENGINE CONTROL SYSTEM (5.6L) (DTC/CIRCUIT DIAGNOSIS) (2 OF 9))DTC/CIRCUIT DIAGNOSISDTC P0128: THERMOSTAT FUNCTIONDTC LOGICDTC CONFIRMATION PROCEDURE
2019 Infiniti Q70 3.7 Luxe, AWD

DTC Confirmation Procedure

2019 Infiniti Q70 3.7 Luxe, AWDSECTION DTC Confirmation Procedure
WARNING: This page is about a different variant/trim than selected.
  1. PRECONDITIONING-I 

    If DTC Confirmation Procedure has been previously conducted, always perform the following procedure before conducting the next test.

    1. Turn ignition switch OFF and wait at least 10 seconds.
    2. Turn ignition switch ON.
    3. Turn ignition switch OFF and wait at least 10 seconds.

    GO TO 2 .

  2. PRECONDITIONING-II 

    SYMBOL With CONSULT

    1. Turn ignition switch ON.
    2. Check the following conditions:

      Ambient temperature

      -10 deg.C (14 deg.F) or more

      A/C switch

      OFF

      Blower fan switch

      OFF
    3. Select "DATA MONITOR" mode of "ENGINE" using CONSULT.
    4. Check the following conditions:

      COOLAN TEMP/S

      (-10) -(+52) deg.C (14-126 deg.F)

    Is the condition satisfied?

    YES

    GO TO 3 .

    NO

    1. Satisfy the condition.
    2. GO TO 3 .
  3. PERFORM DTC CONFIRMATION PROCEDURE-I 

    SYMBOL With CONSULT

    1. Start engine.
    2. Drive the vehicle until the following condition is satisfied.
      CAUTION: Always drive vehicle at safe speed.
      1. STEP 1

        Drive the vehicle under the conditions instructed below until the difference between "COOLAN TEMP/S" and "FUEL T/TMP SE" becomes at least 25 deg.C (77 deg.F).

        COOLAN TEMP/S

        71 deg.C (159 deg.F) or less

        FUEL T/TMP SE

        Less than the value calculated by subtracting 25 deg.C (77 deg.F) from "COOLAN TEMP/S".*
        *: Example

        COOLAN TEMP/S

        FUEL T/TMP SE

        70 deg.C (158 deg.F)

        45 deg.C (113 deg.F) or less

        65 deg.C (149 deg.F)

        40 deg.C (104 deg.F) or less

        60 deg.C (140 deg.F)

        35 deg.C (95 deg.F) or less
      2. STEP 2

        Drive the vehicle at 50 km/h (32 MPH) or more with the difference between "COOLAN TEMP/S" and "FUEL T/TMP SE" maintained at 25 deg.C (77 deg.F) or more.

        NOTE: Keep the accelerator pedal as steady as possible during cruising.
      3. STEP 3

        Drive the vehicle at 50 km/h (32 MPH) or more until "COOLAN TEMP/S" increases by 5 deg.C (41 deg.F).

        NOTE: Keep the accelerator pedal as steady as possible during cruising.

    Is the condition satisfied?

    YES

    GO TO 4 .

    NO

    GO TO 1 .

  4. PERFORM DTC CONFIRMATION PROCEDURE-II 

    SYMBOL With CONSULT

    1. Drive the vehicle until the following condition is satisfied.

      COOLAN TEMP/S

      71 deg.C (159 deg.F) or less
      CAUTION: Always drive vehicle at safe speed.
    2. Check 1st trip DTC.

    Is 1st trip DTC detected?

    YES

    Proceed to Diagnosis Procedure .

    NO

    INSPECTION END

RENDER: 1.0x

NO RELATED

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When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.