AIR CONDITIONING SYSTEM Heater Water Pump Circuit

DESCRIPTION

The heater water pump assembly supplies engine coolant to the heater radiator unit sub-assembly to prevent a decrease in the effectiveness of the heater when the engine is stopped by the hybrid control system. According to signals from the air conditioning amplifier assembly, the hybrid vehicle control ECU assembly operates the semiconductor pwr integration ECU to operate the heater water pump assembly.

WIRING DIAGRAM

B004EY0E05

CAUTION / NOTICE / HINT

Note

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

PROCEDURE


  1. CHECK CAN COMMUNICATION SYSTEM


    1. Using the GTS, check if the CAN communication system is functioning normally.

      Click here

      Result
      Result Proceed to
      CAN communication system DTCs are not output A
      CAN communication system DTCs are output B

    B

    GO TO CAN COMMUNICATION SYSTEM Click here

    A

  2. CHECK SEMICONDUCTOR POWER INTEGRATION ECU


    1. Using a voltmeter, check the signal reading of the semiconductor pwr integration ECU.

      Click here

      OK
      A normal signal reading is output.
      Result
      Proceed to
      OK
      NG

    NG

    CHECK SEMICONDUCTOR POWER INTEGRATION ECU (RESULT OF SIGNAL READING) Click here

    OK

  3. CHECK WIRE HARNESS AND CONNECTOR (SEMICONDUCTOR PWR INTEGRATION ECU - POWER SOURCE AND BODY GROUND)


    1. Remove the semiconductor pwr integration ECU from the No. 1 engine room relay block and No. 1 junction block assembly.

      Click here

      B004FR5C01
      *a

      Component without semiconductor pwr integration ECU connected

      (No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly)

      		 - -

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      1A-1 (ALT) - Body ground Power switch off 11 to 14 V
      1B-1 (BATT) - Body ground Power switch off 11 to 14 V

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1D-14 (GND1) - Body ground Always Below 1 Ω
      1G-5 (GND2) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK WIRE HARNESS AND CONNECTOR (SEMICONDUCTOR PWR INTEGRATION ECU - HEATER WATER PUMP ASSEMBLY AND BODY GROUND)


    1. Disconnect the A11 heater water pump assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1D-12 (L) - A11-2 Always Below 1 Ω
      1D-12 (L) or A11-2 - Body ground Always 10 kΩ or higher
      A11-1 - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  5. CHECK WIRE HARNESS AND CONNECTOR (SEMICONDUCTOR PWR INTEGRATION ECU - HYBRID VEHICLE CONTROL ECU ASSEMBLY)


    1. Disconnect the A80 hybrid vehicle control ECU assembly connector.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1D-4 (-S) - A80-32 (WP) Always Below 1 Ω
      1D-4 (-S) or A80-32 (WP) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  6. CHECK HEATER WATER PUMP ASSEMBLY


    1. Remove the heater water pump assembly.

      Click here

    2. B004FG1C09
      *a

      Component without harness connected

      (Heater Water Pump Assembly)

      Connect a positive (+) lead from the auxiliary battery to terminal 2 (+B) and a negative (-) lead to terminal 1 (-).

      OK
      The heater water pump assembly operates smoothly.

      Note

      Perform this test within 10 seconds to prevent the coil from burning out.

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE HEATER WATER PUMP ASSEMBLY Click here

    OK

  7. CHECK HYBRID VEHICLE CONTROL ECU ASSEMBLY

    B004ELPC27
    *a

    Component with harness connected

    (Hybrid Vehicle Control ECU Assembly)

    		 - -

    1. Reconnect the A80 hybrid vehicle control ECU assembly connector.

    2. Remove the hybrid vehicle control ECU assembly with the connectors still connected.

      Click here

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A80-32 (WP) - Body ground

      • Power switch on (READY)

      • A/C switch off

      		 11 to 15.5 V
      A80-32 (WP) - Body ground

      • Power switch on (READY)

      • A/C switch on

      		 Below 2 V
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE SEMICONDUCTOR PWR INTEGRATION ECU Click here

    NG

    REPLACE HYBRID VEHICLE CONTROL ECU ASSEMBLY Click here