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

A01QU3VE01

CAUTION / NOTICE / HINT

Note

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

PROCEDURE


  1. CHECK HARNESS AND CONNECTOR (HEATER SWITCH ASSEMBLY - BATTERY AND BODY GROUND)


    1. A01QTH2C02
      *a

      Front view of wire harness connector

      (to Heater Switch Assembly)

      Disconnect the heater switch assembly connector.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      G1-4 (IG) - Body ground Ignition switch ON 11 to 14 V
      G1-4 (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
      G1-5 (E) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  2. INSPECT HEATER SWITCH ASSEMBLY


    1. A01QU4QN01

      Remove the heater switch assembly.

    2. Measure the resistance.


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

        Standard Resistance
        Tester Connection Switch 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

    3. Check 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

    OK

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


    1. Disconnect the G1 heater switch assembly connector.

    2. Disconnect the A33 heater assembly connector.

    3. Disconnect the G87 engine stop and start ECU connector.*

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      G1-1 (IN) - A33-3 (IG) Always Below 1 Ω
      G1-1 (IN) - G87-4 (CHI)* Always Below 1 Ω
      A33-3 (IG) - Body ground Always 10 kΩ or higher
      G87-4 (CHI) - Body ground* Always 10 kΩ or higher
      *: w/ Stop and Start System
      Result
      Result Proceed to
      OK (w/o Stop and Start System) A
      OK (w/ Stop and Start System) B
      NG C

    A

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

    B

    REPLACE ENGINE STOP AND START ECU Click here

    C

    REPAIR OR REPLACE HARNESS OR CONNECTOR