HYBRID CONTROL SYSTEM ECU Power Source Circuit

DESCRIPTION

If the power switch is on (IG), the hybrid vehicle control ECU assembly 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

A01KSZBE03

PROCEDURE


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


    1. Turn the power switch on (IG).

    2. A01KTQWC61
      *a

      Component with harness connected

      (Hybrid Vehicle Control ECU Assembly)

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A150-4 (+B1) - Body ground Power switch on (IG) 11 to 14 V
      A149-1 (+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 ASSEMBLY (MREL VOLTAGE) Click here

    OK

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


    1. Disconnect the E135 and E136 hybrid vehicle control ECU assembly connectors.

    2. A01KT57C39
      *a

      Rear view of wire harness connector

      (to Hybrid Vehicle Control ECU Assembly)

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      E135-5 (E01) - Body ground Always Below 1 Ω
      E135-6 (E1) - Body ground Always Below 1 Ω
      E136-4 (E12) - Body ground Always Below 1 Ω
      E136-5 (E02) - Body ground Always Below 1 Ω

    3. Reconnect the E135 and E136 hybrid vehicle control ECU assembly 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 ASSEMBLY (MREL VOLTAGE)


    1. Turn the power switch on (IG).

    2. A01KR9GC50
      *a

      Component with harness connected

      (Hybrid Vehicle Control ECU Assembly)

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

      Standard Voltage
      Tester Connection Condition Specified Condition
      A150-6 (MREL) - Body ground Power switch on (IG) 11 to 14 V
      Result
      Proceed to
      OK
      NG

    NG

    REPLACE HYBRID VEHICLE CONTROL ECU ASSEMBLY for LHD: Click here
    REPLACE HYBRID VEHICLE CONTROL ECU ASSEMBLY for RHD: Click here

    OK

  4. CHECK FUSE (PM-IGCT)


    1. A01KSGPC01
      *1 No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly
      *2 PM-IGCT Fuse

      Remove the PM-IGCT fuse from the No. 1 engine room relay block and No. 1 junction block assembly.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      PM-IGCT fuse terminals Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

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

    OK

  5. CHECK FUSE (IGCT-MAIN)

    Result
    Proceed to
    OK
    NG

    NG

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

    OK

  6. INSPECT RELAY (IGCT)


    1. Remove the IGCT relay from the No. 1 engine room relay block and No. 1 junction block assembly.

    2. A01KTPVC01
      *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 is not applied between terminals 1 and 2 10 kΩ or higher
      Auxiliary battery voltage is 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 (HYBRID VEHICLE CONTROL ECU ASSEMBLY - NO. 1 ENGINE ROOM RELAY BLOCK AND NO. 1 JUNCTION BLOCK ASSEMBLY)


    1. A01KSGPC01
      *1 No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly
      *2 PM-IGCT Fuse

      Remove the PM-IGCT fuse from the No. 1 engine room relay block and No. 1 junction block assembly.

    2. Disconnect the A149 and A150 hybrid vehicle control ECU assembly connectors.

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

      A01KRKXC03
      *1 No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly *2 PM-IGCT Fuse
      *a

      Rear view of wire harness connector

      (to Hybrid Vehicle Control ECU Assembly)

      		 - -
      Standard Resistance
      Tester Connection Condition Specified Condition
      A150-4 (+B1) - 2 (PM-IGCT fuse) Always Below 1 Ω
      A149-1 (+B2) - 2 (PM-IGCT fuse) Always Below 1 Ω

    4. Install the PM-IGCT fuse.

    5. Reconnect the A149 and A150 hybrid vehicle control ECU assembly connectors.

      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


    1. A01KRNZC01
      *1 No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly
      *2 PM-IGCT Fuse
      *3 IGCT-MAIN Fuse

      Remove the IGCT-MAIN fuse and PM-IGCT fuse from the No. 1 engine room relay block and No. 1 junction block assembly.

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

    3. A01KT2KC01
      *1 No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly
      *2 PM-IGCT Fuse
      *3 IGCT Relay
      *4 IGCT-MAIN Fuse

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      3 (IGCT relay) - 2 (IGCT-MAIN fuse) Always Below 1 Ω
      5 (IGCT relay) - 1 (PM-IGCT fuse) Always Below 1 Ω

    4. Install the IGCT-MAIN fuse and PM-IGCT fuse.

    5. Install the IGCT relay.

      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

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


    1. Remove the IGCT relay from the No. 1 engine room relay block and No. 1 junction block assembly.

    2. Disconnect the A150 hybrid vehicle control ECU assembly connector.

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

      A01KRLDC02
      *1 No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly *2 IGCT Relay
      *a

      Rear view of wire harness connector

      (to Hybrid Vehicle Control ECU Assembly)

      		 - -
      Standard Resistance
      Tester Connection Condition Specified Condition
      A150-6 (MREL) - 1 (IGCT relay) Always Below 1 Ω
      A150-6 (MREL) or 1 (IGCT relay) - Body ground and other terminals Always 10 kΩ or higher

    4. Install the IGCT relay.

    5. Reconnect the A150 hybrid vehicle control ECU assembly 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 AND NO. 1 JUNCTION BLOCK ASSEMBLY - BODY GROUND)


    1. Remove the IGCT relay from the No. 1 engine room relay block and No. 1 junction block assembly.

    2. A01KROUC02
      *1 No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly
      *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

    OK

    CHECK FOR INTERMITTENT PROBLEMS Click here

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

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


    1. A01KRNZC01
      *1 No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly
      *2 PM-IGCT Fuse
      *3 IGCT-MAIN Fuse

      Remove the IGCT-MAIN fuse and PM-IGCT fuse from the No. 1 engine room relay block and No. 1 junction block assembly.

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

    3. A01KT2KC01
      *1 No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly
      *2 PM-IGCT Fuse
      *3 IGCT Relay
      *4 IGCT-MAIN Fuse

      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-MAIN fuse) - Body ground and other terminals Always 10 kΩ or higher
      5 (IGCT relay) or 1 (PM-IGCT fuse) - Body ground and other terminals Always 10 kΩ or higher

    4. Install the IGCT-MAIN fuse and PM-IGCT fuse.

    5. Install the IGCT relay.

      Result
      Proceed to
      OK
      NG

    OK

    REPLACE FUSE (IGCT-MAIN)

    NG

  12. REPAIR OR REPLACE HARNESS OR CONNECTOR

    Result
    Proceed to
    NEXT

    NEXT

    REPLACE FUSE (IGCT-MAIN)

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


    1. A01KSGPC01
      *1 No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly
      *2 PM-IGCT Fuse

      Remove the PM-IGCT fuse from the No. 1 engine room relay block and No. 1 junction block assembly.

    2. Disconnect the A149 and A150 hybrid vehicle control ECU assembly connectors.

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

      A01KRKXC03
      *1 No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly *2 PM-IGCT Fuse
      *a

      Rear view of wire harness connector

      (to Hybrid Vehicle Control ECU Assembly)

      		 - -
      Standard Resistance
      Tester Connection Condition Specified Condition
      A150-4 (+B1) or 2 (PM-IGCT fuse) - Body ground and other terminals Always 10 kΩ or higher
      A149-1 (+B2) or 2 (PM-IGCT fuse) - Body ground and other terminals Always 10 kΩ or higher

    4. Install the PM-IGCT fuse.

    5. Reconnect the A149 and A150 hybrid vehicle control ECU assembly connectors.

      Result
      Proceed to
      OK
      NG

    OK

    REPLACE FUSE (PM-IGCT)

    NG

  14. REPAIR OR REPLACE HARNESS OR CONNECTOR

    Result
    Proceed to
    NEXT

    NEXT

    REPLACE FUSE (PM-IGCT)