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

B004QZTE06
*a No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly
*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. Measure the voltage according to the value(s) in the table below.

      B004OOZC48
      *a

      Component with harness connected

      (Hybrid Vehicle Control ECU)

      		 - -
      Standard Voltage
      Tester Connection Condition Specified Condition
      A50-11 (+B1) - Body ground Power switch on (IG) 11 to 14 V
      F3-1 (+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 F2 and F3 hybrid vehicle control ECU connectors.

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

      B004OZTC10
      *a

      Front view of wire harness connector

      (to Hybrid Vehicle Control ECU)

      		 - -
      Standard Resistance
      Tester Connection Condition Specified Condition
      F3-3 (E1) - Body ground Always Below 1 Ω
      F2-34 (E12) - Body ground Always Below 1 Ω
      F2-12 (E01) - Body ground Always Below 1 Ω
      F2-11 (E02) - Body ground Always Below 1 Ω
      F2-10 (E03) - Body ground Always Below 1 Ω

    3. Reconnect the F2 and F3 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. Measure the voltage according to the value(s) in the table below.

      B004OOZC49
      *a

      Component with harness connected

      (Hybrid Vehicle Control ECU)

      		 - -
      Standard Voltage
      Tester Connection Condition Specified Condition
      A50-5 (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 (PM-IGCT)


    1. B004QW5C04
      *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

    3. Install the PM-IGCT fuse.

      Result
      Proceed to
      OK
      NG

    NG

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

    OK

  5. CHECK FUSE (IGCT-IG)


    1. B004OMYC02
      *1 No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly
      *2 IGCT-IG Fuse

      Remove the IGCT-IG 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
      IGCT-IG fuse terminals Always Below 1 Ω

    3. Install the IGCT-IG fuse.

      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. B004OX9C05
      *1 No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly
      *2 IGCT Relay

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

    2. B004PBIC01
      *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 AND NO. 1 JUNCTION BLOCK ASSEMBLY - HYBRID VEHICLE CONTROL ECU)


    1. Disconnect the A50 and F3 hybrid vehicle control ECU connectors.

    2. B004QW5C04
      *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.

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

      B004PDSC03
      *1 No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly *2 PM-IGCT Fuse
      *a

      Front view of wire harness connector

      (to Hybrid Vehicle Control ECU)

      		 - -
      Standard Resistance
      Tester Connection Condition Specified Condition
      A50-11 (+B1) - 2 (PM-IGCT fuse) Always Below 1 Ω
      F3-1 (+B2) - 2 (PM-IGCT fuse) Always Below 1 Ω

    4. Reconnect the A50 and F3 hybrid vehicle control ECU connectors.

    5. Install the PM-IGCT 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 AND NO. 1 JUNCTION BLOCK ASSEMBLY)


    1. B004QJQC03
      *1 No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly
      *2 PM-IGCT Fuse
      *3 IGCT-IG Fuse
      *4 IGCT Relay

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

    2. B004OLKC03
      *1 No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly
      *2 PM-IGCT Fuse
      *3 IGCT-IG 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-IG fuse) Always Below 1 Ω
      5 (IGCT relay) - 1 (PM-IGCT fuse) Always Below 1 Ω

    3. Install the IGCT-IG fuse, PM-IGCT 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 AND NO. 1 JUNCTION BLOCK ASSEMBLY)


    1. Disconnect the A50 hybrid vehicle control ECU connector.

    2. B004OX9C05
      *1 No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly
      *2 IGCT Relay

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

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

      B004PO8C02
      *1 No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly *2 IGCT Relay
      *a

      Front view of wire harness connector

      (to Hybrid Vehicle Control ECU)

      		 - -
      Standard Resistance
      Tester Connection Condition Specified Condition
      A50-5 (MREL) - 1 (IGCT relay) Always Below 1 Ω
      A50-5 (MREL) or 1 (IGCT relay) - Body ground and other terminals Always 10 kΩ or higher

    4. Install the IGCT relay.

    5. Reconnect the A50 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 AND NO. 1 JUNCTION BLOCK ASSEMBLY - BODY GROUND)


    1. B004OX9C05
      *1 No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly
      *2 IGCT Relay

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

    2. B004QV1C02
      *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 - HYBRID VEHICLE CONTROL ECU)


    1. B004QW5C04
      *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 A50 and F3 hybrid vehicle control ECU connectors.

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

      B004PDSC03
      *1 No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly *2 PM-IGCT Fuse
      *a

      Front view of wire harness connector

      (to Hybrid Vehicle Control ECU)

      		 - -
      Standard Resistance
      Tester Connection Condition Specified Condition
      A50-11 (+B1) or 2 (PM-IGCT fuse) - Body ground and other terminals Always 10 kΩ or higher
      F3-1 (+B2) or 2 (PM-IGCT fuse) - Body ground and other terminals Always 10 kΩ or higher

    4. Reconnect the A50 and F3 hybrid vehicle control ECU connectors.

    5. Install the PM-IGCT fuse.

      Result
      Proceed to
      OK
      NG

    OK

    REPLACE FUSE (PM-IGCT)

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR Click here

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


    1. B004QJQC03
      *1 No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly
      *2 PM-IGCT Fuse
      *3 IGCT-IG Fuse
      *4 IGCT Relay

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

    2. B004OLKC03
      *1 No. 1 Engine Room Relay Block and No. 1 Junction Block Assembly
      *2 PM-IGCT Fuse
      *3 IGCT-IG 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-IG 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

    3. Install the IGCT-IG fuse, PM-IGCT fuse and IGCT relay.

      Result
      Proceed to
      OK
      NG

    OK

    REPLACE RELAY (IGCT-IG)

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR Click here

  13. REPAIR OR REPLACE HARNESS OR CONNECTOR

    Result
    Proceed to
    NEXT

    NEXT

    REPLACE FUSE (PM-IGCT)

  14. REPAIR OR REPLACE HARNESS OR CONNECTOR

    Result
    Proceed to
    NEXT

    NEXT

    REPLACE FUSE (IGCT-IG)