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 ECU (heater assembly). The heater pump assembly provides the heater assembly with fuel necessary for combustion, allowing the heater assembly to operate.

WIRING DIAGRAM

A004RZVE01
*a Heater Pump Assembly
*b Heater Assembly

PROCEDURE


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


    1. A004Q3YE01
      Text in Illustration
      *1

      Front view of wire harness connector

      (to Heater Assembly)
      *2

      Front view of wire harness connector

      (to Heater Pump Assembly)

      Disconnect the A54 heater assembly connector.

    2. Disconnect the A55 heater pump assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A54-2 (L) - A55-1 (B2) Always Below 1 Ω
      A55-2 (E2) - Body ground Always Below 1 Ω
      A54-2 (L) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  2. INSPECT HEATER PUMP ASSEMBLY


    1. A004S1RE03
      Text in Illustration
      *1

      Component without harness connected

      (Heater Pump Assembly)

      Disconnect the A55 heater pump assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1 (B2) - 2 (E2) Always 9 to 12 Ω

    3. 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.

      Note


      • 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.

    OK

    REPLACE HEATER ASSEMBLY Click here

    NG

    REPLACE HEATER PUMP ASSEMBLY Click here