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

DTC Code DTC Name
PTC Heater Circuit

DESCRIPTION

PTC heater relays are closed in accordance with signals from the air conditioning amplifier assembly and power is supplied to the quick heater assembly installed on the radiator heater unit.

WIRING DIAGRAM

E290762E08
E290762E09

PROCEDURE

  1. INSPECT PTC HEATER RELAY (HTR SUB NO.1, HTR SUB NO.2, HTR SUB NO.3)

    1. except 1WW:

      E272370E02
      Table 1. Text in Illustration

      *1

      HTR SUB NO.1 Relay, HTR SUB NO.3 Relay

      *2

      HTR SUB NO.2 Relay

      1. Remove the HTR SUB NO.1, HTR SUB NO.2 and HTR SUB NO.3 relays from the engine room No. 2 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 to terminals 1 and 2

        10 kΩ or higher

        Battery voltage is applied to terminals 1 and 2

        Below 1 Ω

    2. for 1WW:

      E272371E02
      Table 2. Text in Illustration

      *1

      HTR SUB NO.2 Relay

      *2

      HTR SUB NO.3 Relay

      *3

      HTR SUB NO.1 Relay

      -

      -

      1. Remove the HTR SUB NO.1, HTR SUB NO.2 and HTR SUB NO.3 relays from the engine room No. 2 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 to terminals 1 and 2

        10 kΩ or higher

        Battery voltage is applied to terminals 1 and 2

        Below 1 Ω

    REPLACE PTC HEATER RELAY (HTR SUB NO.1, HTR SUB NO.2, HTR SUB NO.3)

  2. CHECK AIR CONDITIONING AMPLIFIER ASSEMBLY

    1. U124148E02

      Remove the air conditioning amplifier assembly with its connectors still connected (Click here).

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

      Standard Voltage

      Tester Connection

      Condition

      Specified Condition

      H46-40 (PTC1) - Body ground

      • Engine running (1250 rpm or more)

      • Temperature setting MAX HOT

      • Outside temperature 10°C (50°F) or less

      • Engine coolant temperature 75°C (167°F) or less

      • Headlight dimmer switch off

      • Blower switch off

      11 to 14 V*

      H46-3 (PTC2) - Body ground

      • Engine running (1250 rpm or more)

      • Temperature setting MAX HOT

      • Outside temperature 10°C (50°F) or less

      • Engine coolant temperature 70°C (158°F) or less

      • Headlight dimmer switch off

      • Blower switch off

      H46-39 (PTC3) - Body ground

      • Engine running (1250 rpm or more)

      • Temperature setting MAX HOT

      • Outside temperature 10°C (50°F) or less

      • Engine coolant temperature 65°C (149°F) or less

      • Headlight dimmer switch off

      • Blower switch off

      H46-40 (PTC1) - Body ground

      • Engine running (1250 rpm or more)

      • Temperature setting MAX HOT

      • Outside temperature 10°C (50°F) or less

      • Engine coolant temperature 75°C (167°F) or less

      • Headlight dimmer switch off

      • Blower switch on

      Below 1 V*

      H46-3 (PTC2) - Body ground

      • Engine running (1250 rpm or more)

      • Temperature setting MAX HOT

      • Outside temperature 10°C (50°F) or less

      • Engine coolant temperature 70°C (158°F) or less

      • Headlight dimmer switch off

      • Blower switch on

      H46-39 (PTC3) - Body ground

      • Engine running (1250 rpm or more)

      • Temperature setting MAX HOT

      • Outside temperature 10°C (50°F) or less

      • Engine coolant temperature 65°C (149°F) or less

      • Headlight dimmer switch off

      • Blower switch on
      Table 3. Text in Illustration

      *1

      Component with harness connected

      (Air Conditioning Amplifier Assembly)
      Tip:

      *: After the measurement conditions are met, wait 30 seconds before performing measurements.

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

    (Click here)

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

    1. except 1WW:

      U124056E02
      Table 4. Text in Illustration

      *1

      Component without relay installed

      (Engine Room No. 2 Relay Block)

      *2

      Rear view of wire harness connector

      (to Air Conditioning Amplifier)

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

      2. Disconnect the H46 amplifier connector.

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

        Standard Resistance

        Tester Connection

        Condition

        Specified Condition

        HTR SUB NO.1 relay terminal 2 - H46-40 (PTC1)

        Always

        Below 1 Ω

        HTR SUB NO.2 relay terminal 2 - H46-3 (PTC2)

        HTR SUB NO.3 relay terminal 1 - H46-39 (PTC3)

        HTR SUB NO.1 relay terminal 2 - Body ground

        Always

        10 kΩ or higher

        HTR SUB NO.2 relay terminal 2 - Body ground

        HTR SUB NO.3 relay terminal 1 - Body ground

    2. for 1WW:

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

        U124058E02
        Table 5. Text in Illustration

        *1

        Component without relay installed

        (Engine Room No. 2 Relay Block)

        *2

        Rear view of wire harness connector

        (to Air Conditioning Amplifier)

      2. Disconnect the H46 amplifier connector.

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

        Standard Resistance

        Tester Connection

        Condition

        Specified Condition

        HTR SUB NO.1 relay terminal 1 - H46-40 (PTC1)

        Always

        Below 1 Ω

        HTR SUB NO.2 relay terminal 2 - H46-3 (PTC2)

        HTR SUB NO.3 relay terminal 1 - H46-39 (PTC3)

        HTR SUB NO.1 relay terminal 1 - Body ground

        Always

        10 kΩ or higher

        HTR SUB NO.2 relay terminal 2 - Body ground

        HTR SUB NO.3 relay terminal 1 - Body ground

    REPAIR OR REPLACE HARNESS OR CONNECTOR

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

    1. U124060E02

      except 1WW:

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

      2. Disconnect the A14 heater connector.

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

        Standard Resistance

        Tester Connection

        Condition

        Specified Condition

        HTR SUB NO.1 relay terminal 5 - A14-1 (B)

        Always

        Below 1 Ω

        HTR SUB NO.2 relay terminal 5 - A14-2 (B)

        HTR SUB NO.3 relay terminal 5 - A14-3 (B)

        HTR SUB NO.1 relay terminal 5 - Body ground

        Always

        10 kΩ or higher

        HTR SUB NO.2 relay terminal 5 - Body ground

        HTR SUB NO.3 relay terminal 5 - Body ground
        Table 6. Text in Illustration

        *1

        Component without relay installed

        (Engine Room No. 2 Relay Block)

        *2

        Front view of wire harness connector

        (to Quick Heater Assembly)
    2. U124059E02

      for 1WW:

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

      2. Disconnect the A14 heater connector.

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

        Standard Resistance

        Tester Connection

        Condition

        Specified Condition

        HTR SUB NO.1 relay terminal 3 - A14-2 (B)

        Always

        Below 1 Ω

        HTR SUB NO.2 relay terminal 5 - A14-1 (B)

        HTR SUB NO.3 relay terminal 5 - A14-3 (B)

        HTR SUB NO.1 relay terminal 3 - Body ground

        Always

        10 kΩ or higher

        HTR SUB NO.2 relay terminal 5 - Body ground

        HTR SUB NO.3 relay terminal 5 - Body ground
        Table 7. Text in Illustration

        *1

        Component without relay installed

        (Engine Room No. 2 Relay Block)

        *2

        Front view of wire harness connector

        (to Quick Heater Assembly)

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  5. CHECK HARNESS AND CONNECTOR (PTC HEATER RELAY - BATTERY AND BODY GROUND)

    1. E184863E06

      except 1WW:

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

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

        Standard Voltage

        Tester Connection

        Condition

        Specified Condition

        HTR SUB NO.1 relay terminal 3 - Body ground

        Always

        11 to 14 V

        HTR SUB NO.2 relay terminal 3 - Body ground

        HTR SUB NO.3 relay terminal 3 - Body ground

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

        Standard Resistance

        Tester Connection

        Condition

        Specified Condition

        HTR SUB NO.1 relay terminal 1 - Body ground

        Always

        Below 1 Ω

        HTR SUB NO.2 relay terminal 1 - Body ground

        HTR SUB NO.3 relay terminal 2 - Body ground
        Table 8. Text in Illustration

        *1

        Component without relay installed

        (Engine Room No. 2 Relay Block)
    2. E272369E02

      for 1WW:

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

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

        Standard Voltage

        Tester Connection

        Condition

        Specified Condition

        HTR SUB NO.1 relay terminal 5 - Body ground

        Always

        11 to 14 V

        HTR SUB NO.2 relay terminal 3 - Body ground

        HTR SUB NO.3 relay terminal 3 - Body ground

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

        Standard Resistance

        Tester Connection

        Condition

        Specified Condition

        HTR SUB NO.1 relay terminal 2 - Body ground

        Always

        Below 1 Ω

        HTR SUB NO.2 relay terminal 1 - Body ground

        HTR SUB NO.3 relay terminal 2 - Body ground
        Table 9. Text in Illustration

        *1

        Component without relay installed

        (Engine Room No. 2 Relay Block)

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  6. INSPECT QUICK HEATER ASSEMBLY

    1. E140255E22

      Remove the quick heater assembly (Click here).

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      1 (B) - 1 (E)

      Always

      Below 1 kΩ

      2 (B) - 1 (E)

      2 (B) - 2 (E)

      3 (B) - 2 (E)

    REPLACE QUICK HEATER ASSEMBLY

    (Click here)

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

    1. U123820E02

      Disconnect the A15 heater connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      A15-1 (E) - Body ground

      Always

      Below 1 Ω

      A15-2 (E) - Body ground
      Table 10. Text in Illustration

      *1

      Front view of wire harness connector

      (to Quick Heater Assembly)

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

    (Click here)

    REPAIR OR REPLACE HARNESS OR CONNECTOR