AIR CONDITIONING SYSTEM Heater Water Pump Circuit

DESCRIPTION

The heater water pump assembly sends engine coolant to the heater core assembly while the engine is stopped to prevent heater effectiveness from becoming low. Directed by the air conditioning amplifier assembly, the hybrid vehicle control ECU assembly operates the semiconductor pwr integration ECU and drives the heater water pump assembly.

WIRING DIAGRAM

A0021G1E04

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 PWR 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 PWR 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

      A0021IUC01
      *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) - 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 A84 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) - A84-32 (WP) Always Below 1 Ω
      1D-4 (-S) - 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. Disconnect the A11 heater water pump assembly connector.

      Click here

    2. A00214NC03
      *a

      Component without harness connected

      (Heater Water Pump Assembly)

      Connect the auxiliary battery positive (+) lead to terminal 2 of the heater water pump assembly connector and the auxiliary battery negative (-) lead to terminal 1. Then check that the heater water pump assembly operates smoothly.

      OK
      Heater water pump assembly operates smoothly.

      Note

      Complete the check within 10 seconds if there is no water in the heater water pump assembly.

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE HEATER WATER PUMP ASSEMBLY Click here

    OK

  7. CHECK HYBRID VEHICLE CONTROL ECU ASSEMBLY

    A0020MKC26
    *a

    Component with harness connected

    (Hybrid Vehicle Control ECU Assembly)

    		 - -

    1. Reconnect the A84 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
      A84-32 (WP) - Body ground

      • Power switch on (READY)

      • A/C switch off

      		 11 to 14 V
      A84-32 (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