COMBUSTION TYPE POWER HEATER SYSTEM Power Heater Switch Circuit

DESCRIPTION

When the heater switch assembly (power heater switch) 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

B001IBKE02

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. A01XGZLE02
      Text in Illustration
      *a

      Front view of wire harness connector

      (to Heater Switch Assembly [Power Heater Switch])

      Disconnect the heater switch assembly (power heater switch) connector.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      G177-4 (IG) - Body ground Engine switch on (IG) 11 to 14 V
      G177-4 (IG) - Body ground Engine 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
      G177-5 (E) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  2. INSPECT HEATER SWITCH ASSEMBLY (POWER HEATER SWITCH)


    1. A01XHD4E05

      Remove the heater switch assembly (power heater switch) Click here.

    2. 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 (power heater switch) on Below 1 Ω
      4 (IG) - 1 (IN) Heater switch assembly (power heater switch) off 10 kΩor higher

    3. Check operation indicator.


      1. Turn the heater switch assembly (power heater switch) 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.

      Result
      Result Proceed to
      Indicator comes on A
      Indicator does not come on B

    B

    REPLACE HEATER SWITCH ASSEMBLY (POWER HEATER SWITCH) Click here

    A

  3. CHECK HARNESS AND CONNECTOR (HEATER SWITCH ASSEMBLY - HEATER ASSEMBLY)


    1. Disconnect the G177 heater switch assembly (power heater switch) connector.

    2. Disconnect the A97 heater assembly connector.

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

      Standard Resistance
      Tester Connection Switch Condition Specified Condition
      G177-1 (IN) - A97-3 (IG) Always Below 1 Ω
      A97-3 (IG) - Body ground Always 10 kΩor higher

    OK

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

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR