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Home >> Infiniti >> 2016 >> QX70 AWD >> Repair and Diagnosis >> Heating, Ventilation & A/C (HVAC) >> HVAC Control Systems >> Heater & Air Conditioning System (Automatic Air Conditioner) (Basic Inspection And Circuit Diagnosis) >> Circuit Diagnosis >> Magnet Clutch >> Diagnosis Procedure

Diagnosis Procedure

  1. PERFORM SELF - DIAGNOSIS

    Perform self - diagnosis function. Refer to DIAGNOSIS DESCRIPTION  (WITHOUT ACCS) or DIAGNOSIS DESCRIPTION  (WITH ACCS).

    Is the inspection result normal?

    YES 

    INSPECTION END

    NO 

    GO TO STEP 2  .

  2. PERFORM IPDM E/R AUTO ACTIVE TEST

    Perform IPDM E/R auto active test. Refer to DIAGNOSIS DESCRIPTION .

    Does the magnet clutch operate?

    YES - 1 

    G-20 WITH CONSULT: GO TO STEP 5  .

    YES - 2 

    G-21 WITHOUT CONSULT: GO TO STEP 6  .

    NO 

    Check 10A fuse (No. 49, located in IPDM E/R), and GO TO STEP 3  .

  3. CHECK CIRCUIT CONTINUITY BETWEEN IPDM E/R AND COMPRESSOR

    1. Turn ignition switch OFF.
    2. Disconnect IPDM E/R connector and compressor connector.
    3. Check continuity between IPDM E/R harness connector and compressor harness connector.
      IPDM E/R Compressor Continuity
      Connector Terminal Connector Terminal
      E7 48 F43 1 Existed

    Is the inspection result normal?

    YES 

    GO TO STEP 4  .

    NO 

    Repair harness or connector.

  4. CHECK MAGNET CLUTCH CIRCUIT

    Check for operation sound when applying battery voltage direct current to terminal.

    Is the inspection result normal?

    YES 

    Replace IPDM E/R.

    NO - 1 

    VQ37VHR: Replace magnet clutch. Refer to REMOVAL AND INSTALLATION OF COMPRESSOR CLUTCH .

    NO - 2 

    VK50VE: Replace compressor. Refer to COMPRESSOR .

  5. CHECK ECM INPUT SIGNAL - 1

    Check A/C switch signal in "Data monitor". Refer to CONSULT FUNCTION  (WITHOUT ACCS) or CONSULT FUNCTION  (WITH ACCS).

    A/C SWITCH ON : AIR COND SIG On
    A/C SWITCH OFF : AIR COND SIG Off

    Is the inspection result normal?

    YES 

    GO TO STEP 8  .

    NO 

    GO TO STEP 6  .

  6. CHECK REFRIGERANT PRESSURE SENSOR

    G-20 WITH CONSULT

    1. Start the engine.
    2. Check voltage of refrigerant pressure sensor in "Data monitor". Refer to REFERENCE VALUE (VQ37VHR FOR USA AND CANADA), .

    G-21 WITHOUT CONSULT

    1. Start the engine.
    2. Check voltage between ECM harness connector and ground.
      VQ35HR

      (+) (-) Condition Voltage
      ECM -
      connector Terminal
      M107 105 Ground A/C switch: ON
      (Blower motor operates.)      		 Approx. 1.0 - 4.0 V
      VK50VE

      (+) (-) Condition Voltage
      ECM -
      connector Terminal
      F111 90 Ground A/C switch: ON
      (Blower motor operates.)      		 Approx. 1.0 - 4.0 V

    Is the inspection result normal?

    YES 

    • G-20 WITH CONSULT: GO TO STEP 7  .
    • G-21 WITHOUT CONSULT: Repair harness or connector.

    NO 

    Refer to DIAGNOSIS PROCEDURE (VQ37VHR FOR USA AND CANADA), .

  7. CHECK ECM INPUT SIGNAL - 2

    Check blower fan motor switch signal in "Data monitor". Refer to CONSULT FUNCTION  (WITHOUT ACCS) or CONSULT FUNCTION  (WITH ACCS).

    FAN SWITCH ON : HEATER FAN SW On
    FAN SWITCH OFF : HEATER FAN SW Off

    Is the inspection result normal?

    YES 

    GO TO STEP 8  .

    NO 

    Repair harness or connector.

  8. CHECK CAN COMMUNICATION

    Check CAN communication. Refer to TROUBLE DIAGNOSIS FLOW CHART .

    • ECM - IPDM E/R
    • ECM - Unified meter and A/C amp.

    Is the inspection result normal?

    YES 

    Replace ECM.

    NO 

    Repair or replace malfunctioning part(s).

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