DSD Information System
Home >> Toyota >> 2021 >> Highlander LE, 4WD >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 92 (Heating / Air Conditioning System (HV) - Diagnostic Codes (3 Of 3), Circuit Tests & Symptom Tests) >> AIR CONDITIONING SYSTEM (for HV Model) >> DTC P1C7C-49: Hybrid/EV Battery Voltage System Isolation (A/C Area) Internal Electronic Failure [12/2019 - 11/2023] >> Procedure

DTC P1C7C-49: Hybrid/EV Battery Voltage System Isolation (A/C Area) Internal Electronic Failure [12/2019 - 11/2023]: Procedure

WARNING: This page is about a different variant/trim than selected.
  1. CHECK CAN COMMUNICATION SYSTEM 
    1. Using the GTS, check if the CAN communication system is functioning normally.

      Refer to HOW TO PROCEED WITH TROUBLESHOOTING [12/2019 - 10/2021] , or refer to HOW TO PROCEED WITH TROUBLESHOOTING [10/2021 - 10/2022] , or refer to HOW TO PROCEED WITH TROUBLESHOOTING [10/2022 - 11/2023]

      Result

      Result Proceed to
      CAN communication system DTCs are not output A
      CAN communication system DTCs are output B

    Result: 

    B 

    GO TO CAN COMMUNICATION SYSTEM 

    Refer to HOW TO PROCEED WITH TROUBLESHOOTING [12/2019 - 10/2021] , or refer to HOW TO PROCEED WITH TROUBLESHOOTING [10/2021 - 10/2022] , or refer to HOW TO PROCEED WITH TROUBLESHOOTING [10/2022 - 11/2023]

    Result: 

    A 

    See step  2

  2. CLEAR DTC 
    1. Clear the DTCs.

      Powertrain > Hybrid Control > Clear DTCs 

      HINT: 

      When DTC P1C7C-49 is output, the ignition switch cannot be turned to ON (READY), so use the GTS and clear DTC P1C7C-49.

      Result

      Proceed to
      NEXT

    Result: 

    NEXT 

    See step  3

  3. INSPECT COMPRESSOR WITH MOTOR ASSEMBLY 
    WARNING:

    Because the compressor with motor assembly has a high-voltage circuit, wear insulated gloves and pull out the service plug grip to cut off the high-voltage circuit before inspection.

    1. Turn the ignition switch to ON (READY).
    2. Prepare the vehicle according to the table below for 3 minutes.
      Item Condition
      Blower Speed HI
      Set Temperature MAX COLD
      A/C Switch On
    3. Turn the ignition switch off.
    4. Remove the service plug grip.

      Refer to REMOVAL [12/2019 - 10/2022] , or refer to REMOVAL [10/2022 - 11/2023]

      WARNING:

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

      NOTE:

      After removing the service plug grip, turning the ignition switch to ON (READY) may cause a malfunction. Do not turn the ignition switch to ON (READY) with the service plug grip removed.

    5. Disconnect the m1 compressor with motor assembly connector.
      GTY938289Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Component without harness connected
      (Compressor with Motor Assembly)
    6. Using a megohmmeter, measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      m1-1 (PE) - Body ground Always 2 MΩ or higher
      m1-2 (PB) - Body ground Always 2 MΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPLACE COMPRESSOR WITH MOTOR ASSEMBLY 

    Refer to REMOVAL [12/2019 - 10/2022] , or refer to REMOVAL [10/2022 - 11/2023]

    Result: 

    OK 

    See step  4

  4. INSPECT AIR CONDITIONING CYCLE 
    WARNING:

    Because the compressor with motor assembly has a high-voltage circuit, wear insulated gloves and pull out the service plug grip to cut off the high-voltage circuit before inspection.

    1. Reconnect the m1 the compressor with motor assembly connector.
    2. Install the service plug grip.

      Refer to INSTALLATION [12/2019 - 11/2023]

    3. Turn the ignition switch to ON (READY).
    4. Set the A/C temperature to 25°C (77°F) and blower switch to LO and then operate the compressor with motor assembly for 10 minutes to circulate the refrigerant and collect as much compressor oil as possible in the compressor with motor assembly.
    5. Turn the ignition switch off.
    6. Using a spot cooler or other tool, cool down the compressor with motor assembly for 30 minutes, or leave the vehicle overnight before inspection.
      NOTE:

      Do not operate the compressor before inspection.

    7. Remove the service plug grip.

      Refer to REMOVAL [12/2019 - 10/2022] , or refer to REMOVAL [10/2022 - 11/2023]

      WARNING:

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

      NOTE:

      After removing the service plug grip, turning the ignition switch to ON (READY) may cause a malfunction. Do not turn the ignition switch to ON (READY) with the service plug grip removed.

    8. Disconnect the m1 compressor with motor assembly connector.
      GTY938289Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Component without harness connected
      (Compressor with Motor Assembly)
    9. Using a megohmmeter, measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      m1-1 (PE) - Body ground Always 3 MΩ or higher
      m1-2 (PB) - Body ground Always 3 MΩ or higher
      NOTE:

      If the results are out of the specified range, replace the compressor without operating it.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE COMPRESSOR WITH MOTOR ASSEMBLY 

    Refer to REMOVAL [12/2019 - 10/2022] , or refer to REMOVAL [10/2022 - 11/2023]

    Result: 

    NG 

    REPLACE AIR CONDITIONING CYCLE 

Diesel-Data.com