AIR CONDITIONING SYSTEM, Diagnostic DTC:B1476/76

DTC Code DTC Name
B1476/76 A/C Inverter Load System Malfunction

DESCRIPTION

The operation of the compressor with motor assembly is stopped and a DTC is stored if the rotation load is too large or too small while the compressor with motor assembly is operating.

Possible causes are refrigerant leaks, overcharged refrigerant, insufficient cooling because of a condenser fan circuit malfunction, or compressor lock.

DTC No. DTC Detection Condition Trouble Area
B1476/76 Motor rotation load while the compressor is operating is too large or too small

  • Refrigerant volume


  • Compressor with motor assembly


  • Cooling fan system

  • CAN communication system

CAUTION / NOTICE / HINT

CAUTION:


  • Wear insulated gloves and pull out the service plug grip before inspection as procedures may require disconnecting high-voltage connectors. Carry the removed service plug in your pocket to prevent other technicians from accidentally reconnecting it while you are servicing the vehicle.

  • Do not touch the high-voltage connectors or terminals for 10 minutes after the service plug grip is removed.

Note


  • After turning the ignition switch off, waiting time may be required before disconnecting the cable from the negative (-) auxiliary battery terminal. Therefore, make sure to read the disconnecting the cable from the negative (-) auxiliary battery terminal notices before proceeding with work Click here.

  • The hybrid control system and air conditioning system output DTCs separately. Inspect DTCs following the diagnosis procedure for the hybrid control system first if any DTCs from those systems are output simultaneously.

PROCEDURE


  1. CHECK CAN COMMUNICATION SYSTEM


    1. Use the GTS to check if the CAN communication system is functioning normally.

      OK
      CAN DTC is not output
      Result
      Result Proceed to
      OK A
      NG*1 B
      NG*2 C

      • *1: w/ Toyota Safety Sense

      • *2: w/o Toyota Safety Sense


    B

    GO TO CAN COMMUNICATION SYSTEM (w/ Toyota Safety Sense) Click here

    C

    GO TO CAN COMMUNICATION SYSTEM (w/o Toyota Safety Sense) Click here

    A

  2. PERFORM ACTIVE TEST USING GTS (CONTROL THE ELECTRIC COOLING FAN)


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON (IG).

    3. Turn the GTS on.

    4. Enter the following menus: Power train / Engine and ECT / Active Test.

    5. According to the display on the GTS, perform the Active Test.

      Engine and ECT
      Tester Display Test Part Control Range Diagnostic Note
      Control the Electric Cooling Fan Control electric cooling fan motor ON or OFF

      Perform this text when the following conditions are met:


      • Ignition switch is ON (IG).

      • Engine is stopped.

      • Shift lever in P.
      OK
      Electric cooling fan operates smoothly.

    NG

    GO TO COOLING FAN SYSTEM Click here

    OK

  3. CHECK REFRIGERANT PRESSURE


    1. Install a manifold gauge set.


    2. Turn the ignition switch to ON (READY).

    3. A004EM9E01

      Read the manifold gauge pressure when the following conditions are established.


      1. Prepare the vehicle according to the chart below.

        Item Condition
        Vehicle Doors All fully open
        Temperature Setting MAX COLD
        Blower Speed HI
        A/C switch ON
        R/F Switch

        RECIRCULATION

        (25 to 35°C (77 to 95°F))
        Standard Pressure
        Low pressure side
        0.15 to 0.25 MPa (1.5 to 2.5 kgf/cm2, 21.3 to 35.6 psi)
        High pressure side
        1.37 to 1.57 MPa (14 to 16 kgf/cm2, 199 to 228 psi)
        Result
        Result Proceed to
        OK A
        NG*1 B
        NG*2 C

        • *1: for HFC-134a(R134a)

        • *2: for HFO-1234yf(R1234yf)


    A

    REPLACE COMPRESSOR WITH MOTOR ASSEMBLY Click here

    B

    CHARGE REFRIGERANT Click here

    C

    CHARGE REFRIGERANT Click here