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.

Quick Heater Assembly Operation Condition
Control ECU Condition
Air Conditioning Amplifier Assembly Power switch on (READY)
Combination switch assembly off
Blower switch: on
Temperature settings: MAX HOT
IDH terminal signal less than 1 V (Inverter with converter assembly overload not detected)

  • Engine coolant temperature 60°C (140°F) or lower (2 PTC heater relays operating)

  • Engine coolant temperature 64°C (147°F) or lower (1 PTC heater relay operating)
Ambient temperature 10°C (50°F) or lower

WIRING DIAGRAM

B000PBWE02

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

  • Inspect the fuses for circuits related to this system before performing the following procedure.

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 P53 and P54 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 Diagnostic Note
      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
      P133-1 (L) - Body ground Perform Active Test and select "OFF" item 11 to 14 V
      Perform Active Test and select "ON" item Below 1 V
      P133-2 (L) - Body ground Perform Active Test and select "OFF" item 11 to 14 V
      Perform Active Test and select "ON" item Below 1 V
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

    NG

  5. 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

    NG

    CHECK QUICK HEATER ASSEMBLY Click here

    OK

  6. READ VALUE USING GTS (PTC HEATER NO.1 INPUT SIGNAL, PTC HEATER NO.2 INPUT SIGNAL)


    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
      PTC Heater No.1 Input Signal Quick heater assembly input status OFF or ON

      OFF: Quick heater assembly does not operate

      ON: Quick heater assembly operates

      		 -
      PTC Heater No.2 Input Signal Quick heater assembly input status OFF or ON

      OFF: Quick heater assembly does not operate

      ON: Quick heater assembly operates

      		 -

      Body Electrical > Power Integration No.2 > Data List
      Tester Display
      PTC Heater No.1 Input Signal
      PTC Heater No.2 Input Signal
      OK
      Display changes according to quick heater operation.
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) Click here

    OK

  7. READ VALUE USING GTS (PTC HEATER NO.1 OUTPUT SIGNAL, PTC HEATER NO.2 OUTPUT SIGNAL)


    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
      PTC Heater No.1 Output Signal Quick heater assembly output status OFF or ON

      OFF: Quick heater assembly does not operate

      ON: Quick heater assembly operates

      		 -
      PTC Heater No.2 Output Signal Quick heater assembly output status OFF or ON

      OFF: Quick heater assembly does not operate

      ON: Quick heater assembly operates

      		 -

      Body Electrical > Power Integration No.2 > Data List
      Tester Display
      PTC Heater No.1 Output Signal
      PTC Heater No.2 Output Signal
      OK
      Display changes according to quick heater operation.
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE NO. 2 SEMICONDUCTOR POWER INTEGRATION ECU Click here

    OK

  8. CHECK QUICK HEATER ASSEMBLY


    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 / Air Conditioner / Active Test.

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


      Body Electrical > Air Conditioner > Active Test
      Tester Display Measurement Item Control Range Diagnostic Note
      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
    6. B000PA7C02
      *a

      Front view of wire harness connector

      (to Quick Heater Assembly)

      Disconnect the quick heater assembly connectors.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      P53-2 (B) - Body ground

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

      • Heater level is 1

      		 Below 1 V → 11 to 14 V
      P54-2 (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

    REPLACE QUICK HEATER ASSEMBLY Click here

    OK

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


    1. Disconnect the p53 and p54 quick heater assembly connectors.

    2. Disconnect the P133 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
      P53-2 (B) - P133-1 (L) Always Below 1 Ω
      P54-2 (B) - P133-2 (L) Always Below 1 Ω
      P53-1 (E) - Body ground Always Below 1 Ω
      P54-1 (E) - Body ground Always Below 1 Ω
      P53-2 (B) - P133-1 (L) - Other terminals and body ground Always 10 kΩ or higher
      P54-2 (B) or P133-2 (L) - Other terminals and body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE NO. 2 SEMICONDUCTOR POWER INTEGRATION ECU Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  10. CHECK QUICK HEATER ASSEMBLY


    1. Disconnect the P53 and P43 quick heater assembly connectors.

    2. Turn the air conditioning system off.

    3. Turn the air conditioning system on.

    4. Connect the GTS to the DLC3.

    5. Turn the power switch on (IG).

    6. Turn the GTS on.

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

    8. 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

    NG

    REPLACE QUICK HEATER ASSEMBLY Click here

    OK

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


    1. Disconnect the P53 and P54 quick heater assembly connectors.

    2. Disconnect the P133 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
      P53-2 (B) - P133-1 (L) Always Below 1 Ω
      P54-2 (B) - P133-2 (L) Always Below 1 Ω
      P53-2 (B) - P133-1 (L) - Other terminals and body ground Always 10 kΩ or higher
      P54-2 (B) or P133-2 (L) - Other terminals and body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE NO. 2 SEMICONDUCTOR POWER INTEGRATION ECU Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR