COMBUSTION TYPE POWER HEATER SYSTEM Power Heater Switch Circuit

DTC Code DTC Name
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

E184679E02

CAUTION / NOTICE / HINT

Note:

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

Tip:

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. E176907E06

      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

    REPLACE HEATER SWITCH ASSEMBLY (POWER HEATER SWITCH)

    (Click here)

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

    1. U123706E01

      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
      Table 1. Text in Illustration

      *1

      Front view of wire harness connector

      (Heater Switch Assembly [Power Heater Switch])

    REPAIR OR REPLACE HARNESS OR CONNECTOR

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

    1. U123701E02

      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
      Table 2. Text in Illustration

      *1

      Front view of wire harness connector

      (to Heater Assembly)

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

    (Click here)

    REPAIR OR REPLACE HARNESS OR CONNECTOR