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Inspection Procedure

NOTE: When using the Techstream with the engine switch off to troubleshoot: Connect the Techstream to the vehicle, and turn a courtesy switch on and off at 1.5 second intervals until communication between the Techstream and vehicle begins.
  1. CHECK HARNESS AND CONNECTOR (NO. 2 MAIN BODY ECU - OVERHEAD JUNCTION BLOCK) 
    1. Disconnect the L33 ECU connector.
    2. Disconnect the R12 junction block connector.
    3. Measure the resistance and voltage according to the value (s) in the tables below.

    Standard Resistance 

    TESTER CONNECTION SPECIFIED CONDITION CHART

    Tester Connection Condition Specified Condition
    L33-10 (MPX) - R12-2 (LIN) Always Below 1 Ω
    L33-10 (MPX) - Body ground Always 10 kΩ or higher

    Standard Voltage 

    TESTER CONNECTION SPECIFIED CONDITION CHART

    Tester Connection Condition Specified Condition
    L33-10 (MPX) - Body ground Always Below 1 V

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Fig 1: Checking Harness And Connector (No. 2 Main Body ECU - Overhead Junction Block)
    G05764922Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: Go to next Step 

  2. CHECK OVERHEAD JUNCTION BLOCK (BATTERY VOLTAGE AND GROUND) 
    1. Disconnect the R7 junction block connector.
    2. Measure the resistance and voltage according to the value (s) in the tables below.

    Standard Resistance 

    TESTER CONNECTION SPECIFIED CONDITION CHART

    Tester Connection Condition Specified Condition
    R7-16 (GND9) - Body ground Always Below 1 Ω

    Standard Voltage 

    TESTER CONNECTION SPECIFIED CONDITION CHART

    Tester Connection Condition Specified Condition
    R7-6 (+B2) - Body ground Always 11 to 14 V

    NG: REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Fig 2: Identifying R7 Junction Block Connector
    G05764923Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

    OK: Go to next Step 

  3. CHECK OVERHEAD JUNCTION BLOCK 
    1. Temporarily replace the overhead junction block with a new or normally functioning one (See DISASSEMBLY ).
    2. Clear the DTC (See DTC CHECK / CLEAR ).
  4. CHECK FOR DTC 
    1. Recheck for DTCs (See DTC CHECK / CLEAR ).

    Result 

    RESULT CHART

    Result Proceed to
    DTC B2405 is not output A
    DTC B2405 is output B

    B: REPLACE NO. 2 MAIN BODY ECU  (See REMOVAL )

    A: END (OVERHEAD JUNCTION BLOCK IS DEFECTIVE)