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ECM Power Source Circuit: Wiring Diagram

Fig 1: ECM Power Source - Wiring Diagram
G04110832Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  1. INSPECT HV CONTROL ECU (+B, +B1 VOLTAGE) 
    1. Turn the ignition switch ON.
    2. Measure the voltage between the terminals of the H34 and H31 HV Control ECU connectors.

      Standard voltage 

      TESTER CONNECTION AND SPECIFIED CONDITION

      Tester Connection Specified Condition
      +B1 (H34-2) - E1 (H31-5) 9 to 14 V
      +B2 (H34-1) - E1 (H31-5) 9 to 14 V
      Fig 2: Inspecting HV Control ECU (+B, +B1 Voltage)
      G04110833Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: PROCEED TO NEXT CIRCUIT INSPECTION SHOWN ON  PROBLEM SYMPTOMS TABLE  

    NG: GO TO NEXT STEP 

  2. CHECK HARNESS AND CONNECTOR (HV CONTROL ECU - BODY GROUND) 
    1. Disconnect the H31 HV Control ECU connector.
    2. Measure the resistance between the HV Control ECU and body ground.

      Standard resistance (Check for open) 

      TESTER CONNECTION AND SPECIFIED CONDITION

      Tester Connection Specified Condition
      E1 (H31-5) - Body ground Below 1 Ω
    3. Reconnect the HV Control ECU connector.

    NG: REPAIR OR REPLACE HARNESS AND CONNECTOR 

    Fig 3: Identifying H31 HV Control ECU Connector
    G04110834Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: GO TO NEXT STEP 

  3. INSPECT HV CONTROL ECU (IGSW VOLTAGE) 
    1. Turn the ignition switch ON.
    2. Measure the voltage between the terminals of the H29 and H31 HV Control ECU connectors.

      Standard voltage 

      TESTER CONNECTION AND SPECIFIED CONDITION

      Tester Connection Specified Condition
      IGSW (H29-9) - E1 (H31-5) 9 to 14 V

    OK: Go to step   6 

    Fig 4: Measuring Voltage Between Terminals Of H29 And H31 HV Control ECU Connectors
    G04110835Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: GO TO NEXT STEP 

  4. CHECK FUSE (IGN FUSE) 
    1. Remove the IGN fuse from the instrument panel J/B.
    2. Measure the IGN fuse resistance.

      Standard resistance: 

      Below 1 Ω 

    3. Reinstall the IGN fuse.

    NG: CHECK FOR SHORT IN ALL HARNESSES AND COMPONENTS CONNECTED TO FUSE 

    Fig 5: Identifying IGN Fuse From Instrument Panel J/B
    G04110836Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: GO TO NEXT STEP 

  5. INSPECT IGNITION SWITCH ASSEMBLY 
    1. Check for continuity between the connector terminals shown in the chart below.

      Standard 

      SWITCH TERMINAL REFERENCE

      Switch Terminal No. Resistance
      LOCK All Terminals No continuity
      ACC 1 - 2 Continuity
      ON 2 - 3, 2 - 4, 3 - 4, 6 - 7 Continuity
      START 1 - 2, 1 - 4, 2 - 4, 6 - 7, 6 - 8, 7 - 8 Continuity
      Fig 6: Identifying Continuity Between Connector Terminals
      G04110837Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPLACE IGNITION SWITCH ASSEMBLY 

    OK: PUSH HARNESS AND CONNECTOR (IGNITION SWITCH ASSEMBLY - HV CONTROL ECU) 

  6. INSPECT HV CONTROL ECU (MREL VOLTAGE) 
    1. Turn the ignition switch ON.
    2. Measure the voltage between the terminals of the H34 and H31 HV Control ECU connectors.

      Standard voltage 

      TESTER CONNECTION AND SPECIFIED CONDITION

      Tester Connection Specified Condition
      MREL (H34-12) - E1 (H31-5) 9 to 14 V

    NG: REPLACE HYBRID VEHICLE CONTROL ECU 

    Fig 7: Measuring Voltage Between Terminals Of H34 And H31 HV Control ECU Connectors
    G04110838Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: GO TO NEXT STEP 

  7. CHECK FUSE (IGCT NO.2 FUSE) 
    1. Remove the IGCT No.2 fuse from the R/B No.3.
    2. Measure the IGCT No.2 fuse resistance.

      Standard resistance: 

      Below 1 Ω 

    3. Reinstall the IGCT No.2 fuse.
      Fig 8: Identifying IGCT No.2 Fuse From R/B No.3
      G04110839Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: CHECK FOR SHORT IN ALL HARNESSES AND COMPONENTS CONNECTED TO FUSE 

    OK: GO TO NEXT STEP 

  8. INSPECT IGCT RELAY 
    1. Remove the IGCT relay from the engine room R/B.
    2. Measure the IGCT relay resistance.

      Standard resistance 

      TESTER CONNECTION AND SPECIFIED CONDITION

      Tester Connection Specified Condition
      3 - 5 10 kΩ or higher
      Below 1 Ω (Apply battery voltage between terminals 1 and 2)

    NG: REPLACE INTEGRATION RELAY 

    Fig 9: Identifying IGCT Relay Resistance
    G04110840Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: GO TO NEXT STEP 

  9. CHECK HARNESS AND CONNECTOR (IGCT RELAY- HV CONTROL ECU, IGCT RELAY - BODY GROUND) 
    1. Check the harness and the connectors between the integration relay and the HV Control ECU.
      1. Remove the IGCT relay from the engine room R/B.
      2. Disconnect the H34 HV Control ECU connector.
      3. Measure the resistance between the wire harness side connectors.

        Standard resistance (Check for open) 

        TESTER CONNECTION AND SPECIFIED CONDITION

        Tester Connection Specified Condition
        IGCT relay (1)- MREL (H34-12) Below 1 Ω

        Standard resistance (Check for short) 

        TESTER CONNECTION AND SPECIFIED CONDITION

        Tester Connection Specified Condition
        IGCT relay (1) or MREL (H34-12) - Body ground 10 kΩ or higher
    2. Check the harness and the connectors between the integration relay and body ground.
      1. Remove the integration relay from the engine room R/B.
      2. Measure the resistance between the wire harness side connector and body ground.

        Standard resistance (Check for open) 

        TESTER CONNECTION AND SPECIFIED CONDITION

        Tester Connection Specified condition
        IGCT relay (2) - Body ground Below 1 Ω
        Fig 10: Identifying H34 HV Control ECU Connector
        G04110841Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    NG: REPAIR OR REPLACE HARNESS AND CONNECTOR 

    OK: CHECK AND REPAIR HARNESS AND CONNECTOR (TERMINAL +B OF HV CONTROL ECU - BATTERY POSITIVE TERMINAL) 

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