COMBUSTION TYPE POWER HEATER SYSTEM Power Heater Fuel Pump Circuit

DESCRIPTION

When the power heater switch is turned on, the heater pump assembly receives a drive voltage from the power heater ECU (combustion heater assembly). The heater pump assembly provides the combustion heater with fuel necessary for combustion, allowing the combustion heater to operate.

WIRING DIAGRAM

A0119TSE01

INSPECTION PROCEDURE

PROCEDURE


  1. CHECK HARNESS AND CONNECTOR (COMBUSTION HEATER ASSEMBLY - HEATER PUMP ASSEMBLY)


    1. A0119BCE01
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Power Heater ECU (Combustion Heater Assembly))
      *2

      Front view of wire harness connector

      (to Heater pump assembly)

      Disconnect the A45 power heater ECU (combustion heater assembly) connector.

    2. Disconnect the A42 heater pump assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A45-2 (L) - A42-1 (+B) Always Below 1 Ω
      A45-2 (L) - Body ground Always 10 kΩ or higher

    4. Reconnect the heater pump assembly connector.

    5. Reconnect the power heater ECU (combustion heater assembly) connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


    1. Disconnect the A42 heater pump assembly connector.

    2. A011B2ME01
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Heater pump assembly)

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A42-2 (E2) - Body ground Always Below 1 Ω

    3. Reconnect the heater pump assembly connector.


    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. INSPECT HEATER PUMP ASSEMBLY


    1. Disconnect the A42 heater pump assembly connector.

    2. A011BGME01
      Text in Illustration
      *1

      Component without harness connected

      (Heater pump assembly)

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1 (+B) - 2 (E2) Always 9 to 12 Ω

    3. Inspect heater pump assembly operation.


      1. Connect the positive (+) lead from the battery to terminal 1 and the negative (-) lead to terminal 2, and check the pressure of the hose by hand.

        CAUTION:


        • This inspection must be done quickly (within 10 seconds) to prevent damage to the heater pump assembly.

        • Always switch the voltage on and off on the battery side, not the heater pump assembly side.

        • Keep the heater pump assembly as far away from the battery as possible.

        OK
        Pressure is applied to the hose.

    4. Reconnect the heater pump assembly connector.


    NG

    REPLACE HEATER PUMP ASSEMBLY Click here

    OK

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