AIR CONDITIONING SYSTEM(for Manual 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 Engine running
Combination switch assembly (ECO mode switch) off
Blower motor on
Temperature set to MAX HOT

IDH terminal signal less than 1 V

(Inverter with converter assembly overload not detected)

  • Engine coolant temperature 65°C or less (3 heaters operate)

  • Engine coolant temperature 70°C or less (2 heaters operate)

  • Engine coolant temperature 75°C or less (A heater operates)
Ambient temperature 10°C or less

WIRING DIAGRAM

A01GAZ9E02
A01GC38E01

CAUTION / NOTICE / HINT

Note

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

PROCEDURE


  1. PERFORM ACTIVE TEST USING GTS


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

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

    5. Check the operation by referring to the table below.


      Body Electrical > Air Conditioner > Active Test
      Tester Display Measurement Item Control Range Diagnostic Note
      Heater Active Level Quick heater assembly Min.: 0, Max.: 3 -

      Body Electrical > Air Conditioner > Active Test
      Tester Display
      Heater Active Level
      Result
      Proceed to
      Heater Active Level changes normally
      Heater Active Level does not change normally

    Heater Active Level does not change normally

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here

    Heater Active Level changes normally

  2. INSPECT PTC HEATER RELAY


    1. for Diesel not in Cold Areas:

      A01GB78C01
      *1 PTC HTR NO.2 relay *2 PTC HTR NO.1 relay, PTC HTR NO.3 relay

      1. Remove the PTC heater relays from No. 2 engine room relay block.

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

        Standard Resistance
        Tester Connection Condition Specified Condition
        3 - 5 Battery voltage is not applied between terminals 1 and 2 10 kΩ or higher
        3 - 5 Battery voltage is applied between terminals 1 and 2 Below 1 Ω

    2. for Gasoline, Diesel in Cold Areas:

      A01GA2HC01
      *1 PTC HTR NO.2 relay *2 PTC HTR NO.1 relay

      1. Remove the PTC heater relays from No. 2 engine room relay block.

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

        Standard Resistance
        Tester Connection Condition Specified Condition
        3 - 5 Battery voltage is not applied between terminals 1 and 2 10 kΩ or higher
        3 - 5 Battery voltage is applied between terminals 1 and 2 Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE PTC HEATER RELAY

    OK

  3. CHECK HARNESS AND CONNECTOR (PTC HEATER RELAY - BATTERY)


    1. A01GDI7C01
      *1 No. 2 Engine Room Relay Block
      *2 PTC HTR NO.1 relay
      *3 PTC HTR NO.2 relay
      *4 PTC HTR NO.3 relay

      for Diesel not in Cold Areas:


      1. Remove the PTC heater relays from No. 2 engine room relay block.

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

        Standard Voltage
        PTC HTR NO.1
        Tester Connection Condition Specified Condition
        5 - Body ground Always 11 to 14 V
        2 - Body ground Ignition switch off Below 1 V
        Ignition switch ON 11 to 14 V
        PTC HTR NO.2
        Tester Connection Condition Specified Condition
        5 - Body ground Always 11 to 14 V
        1 - Body ground Ignition switch off Below 1 V
        Ignition switch ON 11 to 14 V
        PTC HTR NO.3
        Tester Connection Condition Specified Condition
        5 - Body ground Always 11 to 14 V
        2 - Body ground Ignition switch off Below 1 V
        Ignition switch ON 11 to 14 V
    2. A01GALTC01
      *1 No. 2 Engine Room Relay Block
      *2 PTC HTR NO.1 relay
      *3 PTC HTR NO.2 relay

      for Gasoline, Diesel in Cold Areas:


      1. Remove the PTC heater relays from No. 2 engine room relay block.

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

        Standard Voltage
        PTC HTR NO.1
        Tester Connection Condition Specified Condition
        5 - Body ground Always 11 to 14 V
        2 - Body ground Ignition switch off Below 1 V
        Ignition switch ON 11 to 14 V
        PTC HTR NO.2
        Tester Connection Condition Specified Condition
        5 - Body ground Always 11 to 14 V
        1 - Body ground Ignition switch off Below 1 V
        Ignition switch ON 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK HARNESS AND CONNECTOR (PTC HEATER RELAY - AIR CONDITIONING AMPLIFIER ASSEMBLY)


    1. for Diesel in not Cold Areas:


      1. Disconnect the G80 air conditioning amplifier assembly connector.

      2. Remove the PTC heater relays from No. 2 engine room relay block.

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

        Standard Resistance
        Tester Connection Condition Specified Condition
        1 - G80-13 (PTC1) Always Below 1 Ω
        2 - G80-19 (PTC2) Always Below 1 Ω
        1 - G80-20 (PTC3) Always Below 1 Ω
        G80-13 (PTC1) - Body ground Always 10 kΩ or higher
        G80-19 (PTC2) - Body ground Always 10 kΩ or higher
        G80-20 (PTC3) - Body ground Always 10 kΩ or higher

    2. for Gasoline, Diesel in Cold Areas:


      1. Disconnect the G80 air conditioning amplifier assembly connector.

      2. Remove the PTC heater relays from No. 2 engine room relay block.

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

        Standard Resistance
        Tester Connection Condition Specified Condition
        1 - G80-13 (PTC1) Always Below 1 Ω
        2 - G80-19 (PTC2) Always Below 1 Ω
        G80-13 (PTC1) - Body ground Always 10 kΩ or higher
        G80-19 (PTC2) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. CHECK HARNESS AND CONNECTOR (PTC HEATER RELAY - QUICK HEATER ASSEMBLY)


    1. for Diesel not in Cold Areas:


      1. Remove the PTC heater relays from No. 2 engine room relay block.

      2. Disconnect the A31 quick heater assembly connector.

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

        Standard Resistance
        PTC HTR NO.1
        Tester Connection Condition Specified Condition
        3 - A31-1 (B) Always Below 1 Ω
        A31-1 (B) - Body ground Always 10 kΩ or higher
        PTC HTR NO.2
        Tester Connection Condition Specified Condition
        3 - A31-2 (B) Always Below 1 Ω
        A31-2 (B) - Body ground Always 10 kΩ or higher
        PTC HTR NO.3
        Tester Connection Condition Specified Condition
        3 - A31-3 (B) Always Below 1 Ω
        A31-3 (B) - Body ground Always 10 kΩ or higher

    2. for Gasoline, Diesel in Cold Areas:


      1. Remove the PTC heater relays from No. 2 engine room relay block.

      2. Disconnect the A31 quick heater assembly connector.

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

        Standard Resistance
        PTC HTR NO.1
        Tester Connection Condition Specified Condition
        3 - A31-1 (B) Always Below 1 Ω
        A31-1 (B) - Body ground Always 10 kΩ or higher
        PTC HTR NO.2
        Tester Connection Condition Specified Condition
        3 - A31-3 (B) Always Below 1 Ω
        A31-3 (B) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


    1. for Diesel not in Cold Areas:


      1. Disconnect the A30 and A35 quick heater assembly connectors.

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

        Standard Resistance
        Tester Connection Condition Specified Condition
        A30-1 (E) - Body ground Always Below 1 Ω
        A35-1 (E) - Body ground Always Below 1 Ω

    2. for Gasoline, Diesel in Cold Areas:


      1. Disconnect the A32 quick heater assembly connector.

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

        Standard Resistance
        Tester Connection Condition Specified Condition
        A32-1 (E) - Body ground Always Below 1 Ω
        A32-2 (E) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  7. INSPECT QUICK HEATER ASSEMBLY


    1. Remove the quick heater assembly.

      Click here

    2. Inspect the quick heater assembly.

      Click here

      Result
      Proceed to
      OK
      NG

    OK

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Click here

    NG

    REPLACE QUICK HEATER ASSEMBLY