COMBUSTION TYPE POWER HEATER SYSTEM Power Heater Switch Circuit

DESCRIPTION

When the heater switch assembly is turned on, the heater assembly sends a drive signal to the heater pump assembly. The heater assembly then receives the fuel necessary for combustion and starts operating.

WIRING DIAGRAM

B0043NNE03

CAUTION / NOTICE / HINT

Note

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

PROCEDURE


  1. CONFIRM MODEL

    Result
    Result Proceed to
    for Sedan A
    for Hatchback, Wagon B

    B

    CHECK HARNESS AND CONNECTOR (HEATER ASSEMBLY - IG POWER SOURCE, BODY GROUND) Click here

    A

  2. CHECK HARNESS AND CONNECTOR (HEATER ASSEMBLY - IG POWER SOURCE, BODY GROUND)


    1. Disconnect the E97 heater switch assembly connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      E97-4 (IG) - Body ground Ignition switch ON 11 to 14 V
      E97-4 (IG) - Body ground Ignition switch off Below 1 V

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      E97-5 (E) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. INSPECT HEATER SWITCH ASSEMBLY


    1. B0042HPC01
      *a

      Component without harness connected

      (Heater Switch Assembly)

      Measure the resistance.


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

        Standard Resistance
        Tester Connection Condition Specified Condition
        4 (IG) - 1 (IN) Heater switch assembly: On Below 1 Ω
        4 (IG) - 1 (IN) Heater switch assembly: Off 10 kΩ or higher

    2. Check the operation indicator.


      1. Turn the heater switch assembly on.

      2. Connect a positive (+) lead from the battery to terminal 4 (IG) and a negative (-) lead to terminal 5 (E), and check that the operation indicator comes on.

        OK
        Indicator comes on.
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE HEATER SWITCH ASSEMBLY Click here

    OK

  4. CHECK HARNESS AND CONNECTOR (HEATER SWITCH ASSEMBLY - HEATER ASSEMBLY, ECM, ENGINE STOP AND START ECU)


    1. Disconnect the A42 heater assembly connector.

    2. Disconnect the E24 engine stop and start ECU connector.*1

    3. Disconnect the A169 ECM connector.*2

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      E97-1 (IN) - A42-3 (IG) Always Below 1 Ω
      E97-1 (IN) - E24-4 (CHI)*1 Always Below 1 Ω
      E97-1 (IN) - A169-32 (MHSW)*2 Always Below 1 Ω
      A42-3 (IG) - Body ground Always 10 kΩ or higher
      E24-4 (CHI) - Body ground*1 Always 10 kΩ or higher
      A169-32 (MHSW) - Body ground*2 Always 10 kΩ or higher

      • *1: w/ Stop and Start System

      • *2: for 1ND-TV

      Result
      Result Proceed to
      OK (Resistance between heater assembly and heater switch assembly is normal) A
      OK (Resistance between heater assembly and ECM is normal) B
      OK (Resistance between heater assembly and engine stop and start ECU is normal) C
      NG D

    A

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

    B

    REPLACE ECM Click here

    C

    REPLACE ENGINE STOP AND START ECU Click here

    D

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  5. CHECK HARNESS AND CONNECTOR (HEATER ASSEMBLY - IG POWER SOURCE, BODY GROUND)


    1. Disconnect the E135 heater switch assembly connector.

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      E135-8 (IG) - Body ground Ignition switch ON 11 to 14 V
      E135-8 (IG) - Body ground Ignition switch off Below 1 V

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      E135-3 (E) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. INSPECT HEATER SWITCH ASSEMBLY


    1. B004236C01
      *a

      Component without harness connected

      (Heater Switch Assembly)

      Measure the resistance.


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

        Standard Resistance
        Tester Connection Condition Specified Condition
        8 (IG) - 5 (IN) Heater switch assembly: On Below 1 Ω
        8 (IG) - 5 (IN) Heater switch assembly: Off 10 kΩ or higher

    2. Check the operation indicator.


      1. Turn the heater switch assembly on.

      2. Connect a positive (+) lead from the battery to terminal 8 (IG) and a negative (-) lead to terminal 3 (E), and check that the operation indicator comes on.

        OK
        Indicator comes on.
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE HEATER SWITCH ASSEMBLY Click here

    OK

  7. CHECK HARNESS AND CONNECTOR (HEATER SWITCH ASSEMBLY - HEATER ASSEMBLY, ECM, ENGINE STOP AND START ECU)


    1. Disconnect the A42 heater assembly connector.

    2. Disconnect the E24 engine stop and start ECU connector.*1

    3. Disconnect the A169 ECM connector.*2

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      E135-5 (IN) - A42-3 (IG) Always Below 1 Ω
      E135-5 (IN) - E24-4 (CHI)*1 Always Below 1 Ω
      E135-5 (IN) - A169-32 (MHSW)*2 Always Below 1 Ω
      A42-3 (IG) - Body ground Always 10 kΩ or higher
      E24-4 (CHI) - Body ground*1 Always 10 kΩ or higher
      A169-32 (MHSW) - Body ground*2 Always 10 kΩ or higher

      • *1: w/ Stop and Start System

      • *2: for 1ND-TV

      Result
      Result Proceed to
      OK (Resistance between heater assembly and heater switch assembly is normal) A
      OK (Resistance between heater assembly and ECM is normal) B
      OK (Resistance between heater assembly and engine stop and start ECU is normal) C
      NG D

    A

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

    B

    REPLACE ECM Click here

    C

    REPLACE ENGINE STOP AND START ECU Click here

    D

    REPAIR OR REPLACE HARNESS OR CONNECTOR