AIR CONDITIONING SYSTEM(for Manual Air Conditioning System) PTC Heater Circuit

DTC Code DTC Name
PTC Heater Circuit

DESCRIPTION

The air conditioning amplifier assembly sends operation signals to the PTC heater relays when the 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.

Table 1. Quick Heater Assembly Operation Condition

Control ECU

Condition

Air Conditioning Amplifier Assembly

Engine running

Blower switch: On

Temperature settings: MAX HOT

Light control switch assembly off

  • Engine coolant temperature: 65°C or lower (3 PTC heater relays operating)

  • Engine coolant temperature: 70°C or lower (2 PTC heater relays operating)

  • Engine coolant temperature: 75°C or lower (1 PTC heater relay operating)

Ambient temperature: 10°C or lower

WIRING DIAGRAM

E267518E02
E267041E02

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

      OK

      Heater Active Level changes normally.

    Result

    Proceed to

    OK

    NG
    NG

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

    Click hereClick here

    OK

  2. INSPECT PTC HEATER RELAY

    1. for PTC heater 600W type.

      1. Remove the PTC heater relays.

        E277707C01

        *a

        Component without harness connected

        (HTR SUB NO. 1 Relay)

        *b

        Component without harness connected

        (HTR SUB NO. 2 Relay)

        *c

        Component without harness connected

        (HTR SUB NO. 3 Relay)

      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 PTC heater 495W type.

      1. Remove the PTC heater relays.

        E277708C01

        *a

        Component without harness connected

        (HTR SUB NO. 1 Relay and HTR SUB NO. 2 Relay)

        *b

        Component without harness connected

        (HTR SUB NO. 3 Relay)

      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 - POWER SOURCE)

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

      Standard Voltage

      HTR SUB NO. 1

      Tester Connection

      Condition

      Specified Condition

      Relay terminal 5 - Body ground*1

      Always

      11 to 14 V

      Relay terminal 3 - Body ground*2

      Always

      11 to 14 V

      Relay terminal 1 - Body ground*1

      Ignition switch off

      Below 1 V

      Relay terminal 1 - Body ground*1

      Ignition switch ON

      11 to 14 V

      Relay terminal 2 - Body ground*2

      Ignition switch off

      Below 1 V

      Relay terminal 2 - Body ground*2

      Ignition switch ON

      11 to 14 V

      Standard Voltage

      HTR SUB NO. 2

      Tester Connection

      Condition

      Specified Condition

      Relay terminal 3 - Body ground

      Always

      11 to 14 V

      Relay terminal 2 - Body ground

      Ignition switch off

      Below 1 V

      Relay terminal 2 - Body ground

      Ignition switch ON

      11 to 14 V

      Standard Voltage

      HTR SUB NO. 3

      Tester Connection

      Condition

      Specified Condition

      Relay terminal 3 - Body ground

      Always

      11 to 14 V

      Relay terminal 1 - Body ground

      Ignition switch off

      Below 1 V

      Relay terminal 1 - Body ground

      Ignition switch ON

      11 to 14 V

      • *1: for PTC Heater 600W Type

      • *2: for PTC Heater 495W Type

    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. Disconnect the E62 air conditioning amplifier assembly connector.

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

      Standard Resistance

      HTR SUB NO. 1

      Tester Connection

      Condition

      Specified Condition

      Relay terminal 2 - E62-13 (PTC1)*1

      Always

      Below 1 Ω

      Relay terminal 1 - E62-13 (PTC1)*2

      Always

      Below 1 Ω

      E62-13 (PTC1) - Body ground

      Always

      10 kΩ or higher

      Standard Resistance

      HTR SUB NO. 2

      Tester Connection

      Condition

      Specified Condition

      Relay terminal 1 - E62-19 (PTC2)

      Always

      Below 1 Ω

      E62-19 (PTC2) - Body ground

      Always

      10 kΩ or higher

      Standard Resistance

      HTR SUB NO. 3

      Tester Connection

      Condition

      Specified Condition

      Relay terminal 2 - E62-20 (PTC3)

      Always

      Below 1 Ω

      E62-20 (PTC3) - Body ground

      Always

      10 kΩ or higher

      • *1: for PTC Heater 600W Type

      • *2: for PTC Heater 495W Type

    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. Disconnect the A6 quick heater assembly connector.

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

      Standard Resistance

      HTR SUB NO. 1

      Tester Connection

      Condition

      Specified Condition

      Relay terminal 3 - A6-2 (B)*1

      Always

      Below 1 Ω

      A6-2 (B) - Body ground*1

      Always

      10 kΩ or higher

      Relay terminal 5 - A6-1 (B)*2

      Always

      Below 1 Ω

      A6-1 (B) - Body ground*2

      Always

      10 kΩ or higher

      Standard Resistance

      HTR SUB NO. 2

      Tester Connection

      Condition

      Specified Condition

      Relay terminal 5 - A6-1 (B)*1

      Always

      Below 1 Ω

      A6-1 (B) - Body ground*1

      Always

      10 kΩ or higher

      Relay terminal 5 - A6-2 (B)*2

      Always

      Below 1 Ω

      A6-2 (B) - Body ground*2

      Always

      10 kΩ or higher

      Standard Resistance

      HTR SUB NO. 3

      Tester Connection

      Condition

      Specified Condition

      Relay terminal 5 - A6-3 (B)

      Always

      Below 1 Ω

      A6-3 (B) - Body ground

      Always

      10 kΩ or higher

      • *1: for PTC Heater 600W Type

      • *2: for PTC Heater 495W Type

    Result

    Proceed to

    OK

    NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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

    1. Disconnect the A7 quick heater assembly connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      A7-1 (E) - Body ground

      Always

      Below 1 Ω

      A7-2 (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. E170870C07

      *a

      Component without harness connected

      (Quick Heater Assembly)

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      A6-1 (B) - A7-1 (E)

      Always

      Below 1 Ω

      A6-2 (B) - A7-1 (E)

      Always

      Below 1 Ω

      A6-2 (B) - A7-2 (E)

      Always

      Below 1 Ω

      A6-3 (B) - A7-2 (E)

      Always

      Below 1 Ω

    Result

    Proceed to

    OK

    NG
    OK

    REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY

    Click hereClick hereClick here

    NG

    REPLACE QUICK HEATER ASSEMBLY

    Click here