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Home >> Lexus >> 2020 >> UX 200 Luxury >> Repair and Diagnosis >> External Pages >> Different car >> Section 71 (Can Communication System (Symptom Tests) (2 Of 3) (Hybrid)) >> CAN COMMUNICATION SYSTEM (for HV Model) >> Check Bus 3 Lines for Short Circuit [10/2019 - 07/2022] >> Procedure

Check Bus 3 Lines for Short Circuit [10/2019 - 07/2022]: Procedure

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  1. CHECK FOR SHORT IN CAN BUS LINES (NO. 5 CAN JUNCTION CONNECTOR) 
    1. Disconnect the cable from the negative (-) auxiliary battery terminal.
    2. Disconnect the No. 5 CAN junction connector.
    3. Measure the resistance according to the value(s) in the table below.
      GTY838092Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to No. 5 CAN Junction Connector)
      *b to Central Gateway ECU (Network Gateway ECU)

      Standard Resistance

      Tester Connection Condition Specified Condition Connected to
      F91-1 (CANH) - F91-12 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω Central gateway ECU (network gateway ECU)
      F91-2 (CANH) - F91-13 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω Central gateway ECU (network gateway ECU)

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  4

    Result: 

    OK 

    See step  2

  2. CHECK FOR SHORT IN CAN BUS LINES (NO. 5 CAN JUNCTION CONNECTOR) 
    1. Disconnect the No. 5 CAN junction connector.
    2. Measure the resistance according to the value(s) in the table below.
      GTY824388Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to No. 5 CAN Junction Connector)
      *b to Radio Receiver Assembly
      *c to DCM (Telematics Transceiver)
      (for Lexus Enform)
      *d to Stereo Component Equalizer Assembly
      (w/ ASC System)

      Standard Resistance

      Tester Connection Condition Specified Condition Connected to
      F92-8 (CANH) - F92-19 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Radio receiver assembly
      F92-9 (CANH) - F92-20 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher DCM (telematics transceiver)*1
      F92-10 (CANH) - F92-21 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Stereo component equalizer assembly*2
      1. *1: w/ Telematics Transceiver
      2. *2: w/ ASC System

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE NO. 5 CAN JUNCTION CONNECTOR 

    Result: 

    NG 

    See step  3

  3. CHECK FOR SHORT IN CAN BUS LINES (ECU OR SENSOR) 
    1. Reconnect all wire harness connectors.
    2. Disconnect the connector that includes terminals CANH and CANL from the ECU or sensor to which the short circuited branch line is connected.

      Refer to TERMINALS OF ECU [10/2019 - 08/2021] , or refer to TERMINALS OF ECU [08/2021 - 07/2022]

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

      Standard Resistance

      Tester Connection Condition Specified Condition
      F61-6 (CA3H) - F61-21 (CA3L) Cable disconnected from negative (-) auxiliary battery terminal 54 to 69 Ω
      GTY779284Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Component with harness connected
      (Central Gateway ECU (Network Gateway ECU))

      HINT: 

      • If the resistance becomes normal (between 54 and 69 Ω) when the connector is disconnected from the ECU or sensor, there may be a short in the ECU or sensor.
      • If the resistance does not become normal when the connector is disconnected from the ECU or sensor, check for a short in the wire harness and repair or replace the wire harness or connector if necessary.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE ECU OR SENSOR 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

  4. CHECK FOR SHORT IN CAN BUS LINES (NO. 5 CAN JUNCTION CONNECTOR - CENTRAL GATEWAY ECU (NETWORK GATEWAY ECU)) 
    1. Disconnect the F61 central gateway ECU (network gateway ECU) connector.
    2. Measure the resistance according to the value(s) in the table below.
      GTY838092Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to No. 5 CAN Junction Connector)
      *b to Central Gateway ECU (Network Gateway ECU)

      Standard Resistance

      Tester Connection Condition Specified Condition
      F91-1 (CANH) - F91-12 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 1 MΩ or higher
      F91-2 (CANH) - F91-13 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 1 MΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE CENTRAL GATEWAY ECU (NETWORK GATEWAY ECU). Refer to  REMOVAL [10/2018 - 07/2022] 

    Result: 

    NG 

    REPAIR OR REPLACE CAN MAIN BUS LINES OR CONNECTOR (NO. 5 CAN JUNCTION CONNECTOR - CENTRAL GATEWAY ECU (NETWORK GATEWAY ECU))