COMBUSTION TYPE POWER HEATER SYSTEM Power Heater Switch Circuit

DESCRIPTION

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

WIRING DIAGRAM

A01IP6IE02

INSPECTION PROCEDURE

Note

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

Tech Tips

Before performing the following procedures, check the battery and generator assembly and confirm that they are operating normally.

PROCEDURE


  1. INSPECT HEATER SWITCH ASSEMBLY (POWER HEATER SWITCH)


    1. A01ITYME02

      Remove the 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) Power heater switch on Below 1 Ω
      4 (IG) - 1 (IN) Power heater switch off 10 kΩ or higher

    3. Apply battery voltage to the power heater switch and check that the operation indicator comes on.

      OK
      Measurement Condition Specified Condition

      Battery positive (+) → Terminal 1 (IN)

      Battery negative (-) → Terminal 5 (E)

      		 Indicator comes on

    4. Apply battery voltage to the power heater switch and check that the illumination comes on.

      OK
      Measurement Condition Specified Condition

      Battery positive (+) → Terminal 3 (ILL+)

      Battery negative (-) → Terminal 2 (ILL-)

      		 Illumination comes on

    NG

    REPLACE HEATER SWITCH ASSEMBLY (POWER HEATER SWITCH) Click here

    OK

  2. CHECK HARNESS AND CONNECTOR (HEATER SWITCH - BODY GROUND)


    1. A01IO8NE03
      Text in Illustration
      *1

      Front view of wire harness connector

      (Heater Switch Assembly [Power Heater Switch])

      Disconnect the H61 switch connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      H61-5 (E) - Body ground Always Below 1 Ω

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


    1. A01IR4PE11
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Heater Assembly)

      Disconnect the A41 heater connector.

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

      Standard Voltage
      Tester Connection Switch Condition Specified Condition
      A41-3 (IG) - Body ground

      Ignition switch ON

      Power heater switch on

      		 11 to 14 V
      A41-3 (IG) - Body ground

      Ignition switch ON

      Power heater switch off

      		 Below 1 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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