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Home >> Infiniti >> 2024 >> QX55 Essential >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> Engine Control System (DTC/Circuit Diagnosis) (4 Of 4) >> DTC/Circuit Diagnosis >> P26A5 Multi-Way Control Valve Position Sensor >> DTC Description
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DTC Description

DTC DETECTION LOGIC 

DTC CONSULT screen terms(Trouble diagnosis content) DTC detection condition
P26A5 00 ENGINE COOLANT B/V A POSI SEN(Engine coolant bypass valve A position sensor circuit range/performance) Diagnosis condition -
Signal (terminal) Multi-way control valve position sensor signal
Threshold ECM detects the following status:
  • A voltage signal transmitted from the multi-way control valve position sensor is 4.8 V or more/4.49 V or less. Outside the above threshold when the valve is moved to the upper side stopper after ignition OFF.
  • A voltage signal transmitted from the multi-way control valve position sensor is 0.63 V or more/0.32 V or less. Outside the threshold when the valve is moved to the lower side stopper after engine start.
Diagnosis delay time -

POSSIBLE CAUSE 

FAIL-SAFE 

Engine operating condition in fail-safe mode
Fail safe mode Vehicle behavior
Others
  • When detecting a malfunction with the valve closed, ECM fully opens the valve.
  • When detecting a malfunction with the valve opened, ECM maintains valve angle.
  • When detecting a malfunction in sensor, ECM fully opens the valve.
  • ECM limits the engine output depending on malfunctions.

DTC CONFIRMATION PROCEDURE 

  1. CHECK DTC PRIORITY 

    If DTC P26A5 is displayed with other DTC, first perform the confirmation procedure (trouble diagnosis) for other DTC.

    Is applicable DTC detected?

    >>

    Perform diagnosis of applicable. Refer to DTC Index

    >>

    GO TO 2.

  2. PRECONDITIONING 

    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.

    TEST CONDITION: Before performing the following procedure, confirm that battery voltage is more than 10 V at ignition switch ON.

    >>

    GO TO 3.

  3. PERFORM DTC CONFIRMATION PROCEDURE-1 
    1. Start the engine and let it idle.
    2. Maintain the following conditions for at least 10 consecutive seconds.
      Engine outlet coolant temperature(engine coolant temperature sensor 1) 10°C (50°F) or more
      Engine oil temperature 135°C (275°F) or less
      Engine speed 4, 500 rpm or less
      Accelerator pedal Fully released
    3. Check 1st trip DTC.

    Is 1st trip DTC detected?

    >>

    Proceed to Diagnosis Procedure .

    >>

    GO TO 4.

  4. PERFORM DTC CONFIRMATION PROCEDURE-2 
    1. Turn ignition switch OFF and wait at least 10 seconds.
    2. Start the engine and let it idle.
    3. Maintain the following conditions for at least 10 consecutive seconds.
      Engine outlet coolant temperature(engine coolant temperature sensor 1) 10°C (50°F) or more
      Engine oil temperature 135°C (275°F) or less
      Engine speed 4, 500 rpm or less
    4. Check 1st trip DTC.

    Is 1st trip DTC detected?

    >>

    Proceed to Diagnosis Procedure .

    >>

    To check malfunction symptom before repair: Refer to Intermittent Incident .

    >>

    Confirmation after repair: INSPECTION END

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