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

DTC Code DTC Name
Heater Control Switch Circuit

DESCRIPTION

The No. 3 heater control sub-assembly is powered through the HTR-IG fuse. The No. 3 heater control sub-assembly transmits operational signals of each switch to the air conditioning amplifier assembly.

WIRING DIAGRAM

E273612E01

CAUTION / NOTICE / HINT

Note:

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

PROCEDURE

  1. INSPECT NO. 3 HEATER CONTROL SUB-ASSEMBLY

    1. E269933C01

      *1

      A/C Switch

      *a

      Max hot position

      *b

      Max cold position

      Measure the resistance.

      1. Remove the No. 3 heater control sub-assembly.

        Click here

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

        Standard Resistance

        Tester Connection

        Switch Condition

        Specified Condition

        2 (B) - 3 (A/C)

        A/C switch on

        Below 1 Ω

        2 (B) - 3 (A/C)

        A/C switch off

        10 kΩ or higher

        7 (B) - 8 (E)

        Max hot position

        Below 1 Ω

        7 (B) - 8 (E)

        Other than max hot position

        10 kΩ or higher

    2. Check that the indicator light comes on.

      1. Turn the A/C switch on.

      2. Connect a positive (+) lead from the battery to terminal 2 (B) and negative (-) lead to terminal 4 (AIND), and check that the indicator light comes on.

        OK

        The indicator light comes on.

    Result

    Proceed to

    OK

    NG
    NG

    REPLACE NO. 3 HEATER CONTROL SUB-ASSEMBLY

    Click here

    OK

  2. CHECK HARNESS AND CONNECTOR (NO. 3 HEATER CONTROL SUB-ASSEMBLY - BATTERY)

    1. E269926C03

      *a

      Front view of wire harness connector

      (to No. 3 Heater Control Sub-assembly)

      Disconnect the No. 3 heater control sub-assembly connector.

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

      Standard Voltage

      Tester Connection

      Switch Condition

      Specified Condition

      G23-2 (B) - Body ground

      Ignition switch ON

      11 to 14 V

      G23-2 (B) - Body ground

      Ignition switch off

      Below 1 V

      G23-7 (B) - Body ground

      Ignition switch ON

      11 to 14 V

      G23-7 (B) - Body ground

      Ignition switch off

      Below 1 V

    Result

    Proceed to

    OK

    NG
    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. CHECK HARNESS AND CONNECTOR (NO. 3 HEATER CONTROL SUB-ASSEMBLY - AIR CONDITIONING AMPLIFIER ASSEMBLY)

    1. Disconnect the G23 No. 3 heater control sub-assembly connector.

    2. Disconnect the G80 air conditioning amplifier assembly connector.

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

      Standard Resistance

      Tester Connection

      Condition

      Specified Condition

      G23-3 (A/C) - G80-2 (A/C)

      Always

      Below 1 Ω

      G23-4 (AIND) - G80-12 (LED)

      Always

      Below 1 Ω

      G23-8 (E) - G80-3 (HEAT)

      Always

      Below 1 Ω

      G23-3 (A/C) - Body ground

      Always

      10 kΩ or higher

      G23-4 (AIND) - Body ground

      Always

      10 kΩ or higher

      G23-8 (E) - Body ground

      Always

      10 kΩ or higher

    Result

    Proceed to

    OK

    NG
    OK

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

    Click hereClick hereClick here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR