HYBRID CONTROL SYSTEM ECU Power Source Circuit

DESCRIPTION

If the power switch is on (IG), the hybrid vehicle control ECU applies current to the MREL terminal to turn the IGCT relay on. This supplies power to the +B1 and +B2 terminals.

WIRING DIAGRAM

Refer to the wiring diagram for DTC P0A08-264.

Click here

B002KAJE01
*a IGCT NO. 3
*b Auxiliary Battery
*c Hybrid Vehicle Control ECU

PROCEDURE


  1. CHECK HYBRID VEHICLE CONTROL ECU (+B1, +B2 VOLTAGE)


    1. Turn the power switch on (IG).

    2. B002HCWC34
      *a

      Component with harness connected

      (Hybrid Vehicle Control ECU)

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A61-4 (+B1) - Body ground Power switch on (IG) 11 to 14 V
      A60-1 (+B2) - Body ground Power switch on (IG) 11 to 14 V

    3. Turn the power switch off.

      Result
      Proceed to
      OK
      NG

    NG

    CHECK HYBRID VEHICLE CONTROL ECU (MREL VOLTAGE) Click here

    OK

  2. CHECK HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU - BODY GROUND)


    1. Disconnect the I115 and I116 hybrid vehicle control ECU connectors.

    2. B002K7OC25
      *a

      Rear view of wire harness connector

      (to Hybrid Vehicle Control ECU)

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      I115-5 (E01) - Body ground Always Below 1 Ω
      I115-6 (E1) - Body ground Always Below 1 Ω
      I116-4 (E12) - Body ground Always Below 1 Ω
      I116-5 (E02) - Body ground Always Below 1 Ω

    3. Reconnect the I115 and I116 hybrid vehicle control ECU connectors.

      Result
      Proceed to
      OK
      NG

    OK

    GO TO PROBLEM SYMPTOMS TABLE Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

  3. CHECK HYBRID VEHICLE CONTROL ECU (MREL VOLTAGE)


    1. Turn the power switch on (IG).

    2. B002HCWC40
      *a

      Component with harness connected

      (Hybrid Vehicle Control ECU)

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A61-6 (MREL) - Body ground Power switch on (IG) 11 to 14 V

    3. Turn the power switch off.

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE HYBRID VEHICLE CONTROL ECU Click here

    OK

  4. CHECK FUSE (IGCT NO. 3)


    1. B002K7PC03
      *1 No. 1 Engine Room Relay Block
      *2 IGCT NO. 3 Fuse

      Remove the IGCT NO. 3 fuse from the No. 1 engine room relay block.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      IGCT NO. 3 fuse terminals Always Below 1 Ω

    3. Install the IGCT NO. 3 fuse.

      Result
      Proceed to
      OK
      NG

    NG

    CHECK HARNESS AND CONNECTOR (NO. 1 ENGINE ROOM RELAY BLOCK - HYBRID VEHICLE CONTROL ECU) Click here

    OK

  5. CHECK FUSE (IGCT)


    1. B002HOWC02
      *1 No. 1 Engine Room Relay Block
      *2 IGCT Fuse

      Remove the IGCT fuse from the No. 1 engine room relay block.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      IGCT fuse terminals Always Below 1 Ω

    3. Install the IGCT fuse.

      Result
      Proceed to
      OK
      NG

    NG

    CHECK HARNESS AND CONNECTOR (NO. 1 ENGINE ROOM RELAY BLOCK) Click here

    OK

  6. INSPECT RELAY (IGCT)


    1. Remove the IGCT relay from the No. 1 engine room relay block.

    2. B002K0KC01
      *1 IGCT Relay

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      3 - 5 Auxiliary battery voltage not applied between terminals 1 and 2 10 kΩ or higher
      Auxiliary battery voltage applied between terminals 1 and 2 Below 1 Ω

    3. Install the IGCT relay.

      Result
      Proceed to
      OK
      NG

    NG

    REPLACE RELAY (IGCT)

    OK

  7. CHECK HARNESS AND CONNECTOR (NO. 1 ENGINE ROOM RELAY BLOCK - HYBRID VEHICLE CONTROL ECU)


    1. B002K7PC03
      *1 No. 1 Engine Room Relay Block
      *2 IGCT NO. 3 Fuse

      Remove the IGCT NO. 3 fuse from the No. 1 engine room relay block.

    2. Disconnect the A60 and A61 hybrid vehicle control ECU connectors.

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

      B002K38C02
      *1 No. 1 Engine Room Relay Block *2 IGCT NO. 3 Fuse
      *a

      Rear view of wire harness connector

      (to Hybrid Vehicle Control ECU)

      		 - -
      Standard Resistance
      Tester Connection Condition Specified Condition
      A61-4 (+B1) - 2 (IGCT NO. 3 fuse) Always Below 1 Ω
      A60-1 (+B2) - 2 (IGCT NO. 3 fuse) Always Below 1 Ω

    4. Reconnect the A60 and A61 hybrid vehicle control ECU connectors.

    5. Install the IGCT NO. 3 fuse.

      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  8. CHECK HARNESS AND CONNECTOR (NO. 1 ENGINE ROOM RELAY BLOCK)


    1. B002KELC02
      *1 No. 1 Engine Room Relay Block
      *2 IGCT Fuse
      *3 IGCT NO. 3 Fuse
      *4 IGCT Relay

      Remove the IGCT fuse, IGCT NO. 3 fuse and IGCT relay from the No. 1 engine room relay block.

    2. B002HD3C03
      *1 No. 1 Engine Room Relay Block
      *2 IGCT Fuse
      *3 IGCT NO. 3 Fuse
      *4 IGCT Relay

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      3 (IGCT relay) - 2 (IGCT fuse) Always Below 1 Ω
      5 (IGCT relay) - 1 (IGCT NO. 3 fuse) Always Below 1 Ω

    3. Install the IGCT fuse, IGCT NO. 3 fuse and IGCT relay.

      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  9. CHECK HARNESS AND CONNECTOR (HYBRID VEHICLE CONTROL ECU - NO. 1 ENGINE ROOM RELAY BLOCK)


    1. Disconnect the A61 hybrid vehicle control ECU connector.

    2. Remove the IGCT relay from the No. 1 engine room relay block.

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

      B002K7BC01
      *1 No. 1 Engine Room Relay Block *2 IGCT Relay
      *a

      Rear view of wire harness connector

      (to Hybrid Vehicle Control ECU)

      		 - -
      Standard Resistance
      Tester Connection Condition Specified Condition
      A61-6 (MREL) - 1 (IGCT relay) Always Below 1 Ω
      A61-6 (MREL) or 1 (IGCT relay) - Body ground and other terminals Always 10 kΩ or higher

    4. Install the IGCT relay.

    5. Reconnect the A61 hybrid vehicle control ECU connector.

      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  10. CHECK HARNESS AND CONNECTOR (NO. 1 ENGINE ROOM RELAY BLOCK - BODY GROUND)


    1. Remove the IGCT relay from the No. 1 engine room relay block.

    2. B002IXWC01
      *1 No. 1 Engine Room Relay Block
      *2 IGCT Relay

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

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

    3. Install the IGCT relay.

      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  11. CHECK HARNESS AND CONNECTOR (NO. 1 ENGINE ROOM RELAY BLOCK)


    1. B002HNEC01
      *1 No. 1 Engine Room Relay Block
      *2 AMD Terminal
      *3 IGCT Fuse

      Disconnect the No. 2 engine room wire from the AMD terminal (No. 1 engine room relay block side).

    2. Remove the IGCT fuse from the No. 1 engine room relay block.

    3. B002H49C01
      *1 No. 1 Engine Room Relay Block
      *2 IGCT Fuse

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      1C-1 (AMD) - 1 (IGCT fuse) Always Below 1 Ω

    4. Install the IGCT fuse.

    5. Reconnect the No. 2 engine room wire.

      Result
      Proceed to
      OK
      NG

    OK

    CHECK FOR INTERMITTENT PROBLEMS Click here

    NG

    CHECK FUSE (DC/DC) Click here

  12. CHECK HARNESS AND CONNECTOR (NO. 1 ENGINE ROOM RELAY BLOCK - HYBRID VEHICLE CONTROL ECU)


    1. B002K7PC03
      *1 No. 1 Engine Room Relay Block
      *2 IGCT NO. 3 Fuse

      Remove the IGCT NO. 3 fuse from the No. 1 engine room relay block.

    2. Disconnect the A60 and A61 hybrid vehicle control ECU connectors.

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

      B002L22C01
      *1 No. 1 Engine Room Relay Block *2 IGCT NO. 3 Fuse
      *a

      Rear view of wire harness connector

      (to Hybrid Vehicle Control ECU)

      		 - -
      Standard Resistance
      Tester Connection Condition Specified Condition
      A61-4 (+B1) or 2 (IGCT NO. 3 fuse) - Body ground and other terminals Always 10 kΩ or higher
      A60-1 (+B2) or 2 (IGCT NO. 3 fuse) - Body ground and other terminals Always 10 kΩ or higher

    4. Reconnect the A60 and A61 hybrid vehicle control ECU connectors.

    5. Install the IGCT NO. 3 fuse.

      Result
      Proceed to
      OK
      NG

    OK

    REPLACE FUSE (IGCT NO. 3)

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR Click here

  13. CHECK HARNESS AND CONNECTOR (NO. 1 ENGINE ROOM RELAY BLOCK)


    1. B002KELC02
      *1 No. 1 Engine Room Relay Block
      *2 IGCT Fuse
      *3 IGCT NO. 3 Fuse
      *4 IGCT Relay

      Disconnect the IGCT fuse, IGCT NO. 3 fuse and IGCT relay from the No. 1 engine room relay block.

    2. B002HD3C03
      *1 No. 1 Engine Room Relay Block
      *2 IGCT Fuse
      *3 IGCT NO. 3 Fuse
      *4 IGCT Relay

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

      Standard Resistance:
      Tester Connection Condition Specified Condition
      3 (IGCT relay) or 2 (IGCT fuse) - Body ground and other terminals Always 10 kΩ or higher
      5 (IGCT relay) or 1 (IGCT NO. 3 fuse) - Body ground and other terminals Always 10 kΩ or higher

    3. Install the IGCT fuse, IGCT NO. 3 fuse and IGCT relay.

      Result
      Proceed to
      OK
      NG

    OK

    REPLACE RELAY (IGCT)

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR Click here

  14. CHECK FUSE (DC/DC)

    Result
    Proceed to
    OK
    NG

    1. B002H58C01
      *1 No. 1 Engine Room Relay Block
      *2 DC/DC Fuse

      Check the DC/DC fuse in the No. 1 engine room relay block for improper installation.

      OK
      The fuse is installed securely.

    2. Remove the DC/DC fuse from the No. 1 engine room relay block.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      DC/DC fuse terminals Always Below 1 Ω

    4. Install the DC/DC fuse.

      Result
      Proceed to
      OK
      NG

    OK

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    NG

    REPLACE FUSE (DC/DC)

  15. REPAIR OR REPLACE HARNESS OR CONNECTOR

    Result
    Proceed to
    NEXT

    NEXT

    REPLACE FUSE (IGCT NO. 3)

  16. REPAIR OR REPLACE HARNESS OR CONNECTOR

    Result
    Proceed to
    NEXT

    NEXT

    REPLACE FUSE (IGCT)