AIR CONDITIONING SYSTEM PTC Heater Circuit

DESCRIPTION

The air conditioning amplifier assembly sends operation signals to the PTC heater relays when quick heater assembly operation conditions are met. Based on the signals from the air conditioning amplifier assembly, the PTC heater relays turn on, and power is supplied to the quick heater assembly installed in the air conditioning radiator assembly.

Symptom Factor
Heating performance is poor when it is cold.

  • No. 2 semiconductor power integration ECU

  • Quick heater assembly

  • Air conditioning amplifier assembly

  • Main body ECU (multiplex network body ECU)

  • Harness or connector

WIRING DIAGRAM

B004V5YE04

CAUTION / NOTICE / HINT

Note

If the auxiliary battery voltage is low, the PTC heater may not operate. When "Operation of Electrical Items Restricted." is displayed on the multi-information display in the combination meter assembly, inspect the auxiliary battery, referring to On-vehicle Inspection for the charging system.

Click here

Tech Tips

If the auxiliary battery voltage is low, the PTC heater may not operate. When "Operation of Electrical Items Restricted." is not displayed on the multi-information display in the combination meter assembly, check the Data List item "Battery Control Count (Body ECU)".

Click here

PROCEDURE


  1. CHECK CAN COMMUNICATION SYSTEM


    1. Using the GTS, check if the CAN communication system is functioning normally.

      Click here

      OK
      CAN communication system DTCs are not output.
      Result
      Proceed to
      OK
      NG

    NG

    GO TO CAN COMMUNICATION SYSTEM Click here

    OK

  2. CHECK CXPI COMMUNICATION SYSTEM


    1. Using the GTS, check if the CXPI communication system is functioning normally.

      Click here

      OK
      CXPI communication system DTCs are not output.
      Result
      Proceed to
      OK
      NG

    NG

    GO TO CXPI COMMUNICATION SYSTEM Click here

    OK

  3. CHECK POWER INTEGRATION SYSTEM


    1. Using the GTS, check if the power integration system is functioning normally.

      Click here

      OK
      Power integration system DTCs are not output.
      Result
      Proceed to
      OK
      NG

    NG

    GO TO POWER INTEGRATION SYSTEM Click here

    OK

  4. CHECK QUICK HEATER ASSEMBLY


    1. Disconnect the quick heater assembly connectors.

    2. Connect the GTS to the DLC3.

    3. Turn the power switch on (IG).

    4. Turn the GTS on.

    5. Enter the following menus: Body Electrical / Air Conditioner / Active Test.

    6. Perform the Active Test according to the display on the GTS.


      Body Electrical > Air Conditioner > Active Test
      Tester Display Measurement Item Control Range Restrict Condition
      Heater Active Level Quick heater assembly

      Min.: 0

      Max.: 2

      Perform this test when the following conditions are met:


      • Power switch on (READY)

      • Air conditioning system is operated

      Body Electrical > Air Conditioner > Active Test
      Tester Display
      Heater Active Level

    7. Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Condition Specified Condition
      G60-2 (B) - Body ground

      • Perform Active Test and select "OFF" → "ON" item

      • Heater level is 1

      		 Below 1 V → 11 to 14 V
      G61-2 (B) - Body ground

      • Perform Active Test and select "OFF" → "ON" item

      • Heater level is 2

      		 Below 1 V → 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    CHECK HARNESS AND CONNECTOR (QUICK HEATER ASSEMBLY - NO. 2 SEMICONDUCTOR POWER INTEGRATION ECU AND BODY GROUND) Click here

    OK

  5. CHECK HARNESS AND CONNECTOR (QUICK HEATER ASSEMBLY - BODY GROUND)


    1. Disconnect the quick heater assembly connectors.

    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      G60-1 (E) - Body ground Always Below 1 Ω
      G61-1 (E) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. INSPECT QUICK HEATER ASSEMBLY


    1. B004SAFC10
      *a

      Component without harness connected

      (Quick Heater Assembly)

      Disconnect the quick heater assembly connectors.

    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      A-2 (B) - A-1 (E) Always Below 10 kΩ
      B-2 (B) - B-1 (E) Always Below 10 kΩ
      Result
      Proceed to
      OK
      NG

    OK

    USE SIMULATION METHOD TO CHECK Click here

    NG

    REPLACE QUICK HEATER ASSEMBLY Click here

  7. CHECK HARNESS AND CONNECTOR (QUICK HEATER ASSEMBLY - NO. 2 SEMICONDUCTOR POWER INTEGRATION ECU AND BODY GROUND)


    1. Disconnect the G60 and G61 quick heater assembly connectors.

    2. Disconnect the G97 No. 2 semiconductor power integration ECU connector.

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      G60-2 (B) - G97-1 (L) - Other terminals and body ground Always 10 kΩ or higher
      G61-2 (B) or G97-2 (L) - Other terminals and body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  8. READ VALUE USING GTS (STATUS OF PTC HEATER NO.1 FUSE, STATUS OF PTC HEATER NO.2 FUSE)


    1. Connect the GTS to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the GTS on.

    4. Enter the following menus: Body Electrical / Power Integration No.1 / Data List.

    5. Read the Data List according to the display on the GTS.


      Body Electrical > Power Integration No.2 > Data List
      Tester Display Measurement Item Range Normal Condition Diagnostic Note
      Status of PTC Heater No.1 Fuse Quick heater assembly fuse Connect or Disconnect

      Connect: Fuse not shut off

      Disconnect: Fuse shut off

      		 -
      Status of PTC Heater No.2 Fuse Quick heater assembly fuse Connect or Disconnect

      Connect: Fuse not shut off

      Disconnect: Fuse shut off

      		 -

      Body Electrical > Power Integration No.2 > Data List
      Tester Display
      Status of PTC Heater No.1 Fuse
      Status of PTC Heater No.2 Fuse
      OK
      The Data List value displays "Connect".
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE NO. 2 SEMICONDUCTOR POWER INTEGRATION ECU Click here

    NG

    REPLACE NO. 2 SEMICONDUCTOR POWER INTEGRATION ECU AND QUICK HEATER ASSEMBLY No. 2 semiconductor power integration ECU: Click here Quick heater assembly: Click here