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Home >> Lexus >> 2019 >> NX 300h >> Repair and Diagnosis >> Accessories & Equipment >> Communication Devices >> Can Communication System - Diagnostic Codes (2 Of 2) & Circuit Tests (1 Of 3) >> Can Communication System >> Main Body ECU Communication Stop Mode [05/2019 - ] >> Procedure

Main Body ECU Communication Stop Mode [05/2019 - ]: Procedure

  1. CHECK FOR OPEN IN CAN BUS WIRE (MAIN BODY ECU [MULTIPLEX NETWORK BODY ECU] BRANCH WIRE) 
    1. Disconnect the cable from the negative (-) auxiliary battery terminal.
    2. Disconnect the main body ECU (multiplex network body ECU) connector.
      GTY833764Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to Main Body ECU [Multiplex Network Body ECU])
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      I48-14 (CANH) - I48-13 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 54 to 69 Ω

      Result

      Proceed to 
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR 

    Result: 

    OK 

    See step  2

  2. CHECK HARNESS AND CONNECTOR (POWER SOURCE CIRCUIT) 
    1. Reconnect the cable to the negative (-) auxiliary battery terminal.
      GTY822003Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Component without harness connected
      (Instrument Panel Junction Block Assembly)
    2. Remove the instrument panel junction block assembly.

      Refer to REMOVAL [05/2019 - ]

    3. reconnect the instrument panel junction block assembly connectors.
    4. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Switch Condition Specified Condition
      A-30 (ACC) - Body ground Power switch on (ACC) 11 to 14 V
      Power switch off Below 1 V
      A-31 (BECU) - Body ground Power switch off 11 to 14 V
      A-32 (IG) - Body ground Power switch on (IG) 11 to 14 V
      Power switch off Below 1 V
    5. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      A-11 (GND1) - Body ground Always Below 1 Ω

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU). Refer to  REMOVAL [05/2019 - ] 

    Result: 

    NG 

    See step  3

  3. CHECK HARNESS AND CONNECTOR (POWER SOURCE CIRCUIT) 
    1. Disconnect the instrument panel junction block assembly connectors.
      GTY818537Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to Instrument Panel Junction Block Assembly)
      - -
    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Switch Condition Specified Condition
      4D-49 - Body ground Power switch off 11 to 14 V
      4F-1 - Body ground Power switch off 11 to 14 V
      4C-28 - Body ground Power switch on (ACC) 11 to 14 V
      Power switch off Below 1 V
      4C-44 - Body ground Power switch on (IG) 11 to 14 V
      Power switch off Below 1 V
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      4D-9 - Body ground Always Below 1 Ω

      Result

      Proceed to 
      OK
      NG

    Result: 

    OK 

    REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY. Refer to  REMOVAL [05/2019 - ] 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT)