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Home >> Lexus >> 2021 >> UX 200 Luxury >> Repair and Diagnosis >> Accessories & Equipment >> Communication Devices >> Can Communication System (Diagnostic Codes & Symptom Tests (1 Of 2)) (Except Hybrid) >> CAN COMMUNICATION SYSTEM (for Gasoline Model) >> Check Bus 1 Lines for Short Circuit [08/2021 - 07/2022] >> Procedure

Check Bus 1 Lines for Short Circuit [08/2021 - 07/2022]: Procedure

  1. CHECK FOR SHORT IN CAN BUS LINES (NO. 2 CAN JUNCTION CONNECTOR) 
    1. Disconnect the cable from the negative (-) auxiliary battery terminal.
    2. Disconnect the No. 2 CAN junction connector.
    3. Measure the resistance according to the value(s) in the table below.
      GTY779160Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to No. 2 CAN Junction Connector)
      *b to No. 8 CAN Junction Connector
      *c to Central Gateway ECU (Network Gateway ECU) *d to Clearance Warning ECU Assembly
      (w/ Parking Support Alert System)
      *e to Forward Recognition Camera *f to Millimeter Wave Radar Sensor Assembly

      Standard Resistance

      Tester Connection Condition Specified Condition Connected to
      F86-1 (CANH) - F86-7 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω No. 8 CAN junction connector
      F86-2 (CANH) - F86-8 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω Central gateway ECU (network gateway ECU)
      F86-3 (CANH) - F86-9 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Clearance warning ECU assembly*1
      F86-5 (CANH) - F86-11 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Forward recognition camera
      F86-6 (CANH) - F86-12 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Millimeter wave radar sensor assembly
      1. *1: w/ Parking Support Alert System

      Result

      Result Proceed to
      OK A
      NG (Line to central gateway ECU (network gateway ECU)) B
      NG (Line to No. 8 CAN junction connector) C
      NG (Line to ECU or sensor) D

    Result: 

    REPLACE NO. 2 CAN JUNCTION CONNECTOR 

    Result: 

    See step  3

    Result: 

    See step  5

    Result: 

    See step  2

  2. CHECK FOR SHORT IN CAN BUS LINES (NO. 2 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.
      GTY779183Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to No. 2 CAN Junction Connector)
      *b to Central Gateway ECU (Network Gateway ECU)

      Standard Resistance

      Tester Connection Condition Specified Condition
      F86-2 (CANH) - F86-8 (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. 2 CAN JUNCTION CONNECTOR - CENTRAL GATEWAY ECU (NETWORK GATEWAY ECU)) 

  3. CHECK FOR SHORT IN CAN BUS LINES (NO. 8 CAN JUNCTION CONNECTOR) 
    1. Reconnect the F86 No. 2 CAN junction connector.
    2. Disconnect the No. 8 CAN junction connector.
    3. Measure the resistance according to the value(s) in the table below.
      GTY1086158Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to No. 8 CAN Junction Connector)
      *b to No. 2 CAN Junction Connector
      *c to Rear Television Camera Assembly
      (w/ Television Camera)
      *d to Blind Spot Monitor Sensor LH
      (w/ Blind Spot Monitor System)
      *e to No. 2 CAN Junction Terminal - -

      Standard Resistance

      Tester Connection Condition Specified Condition Connected to
      N117-4 (CANH) - N117-15 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω No. 2 CAN junction connector
      N117-5 (CANH) - N117-16 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Rear television camera assembly
      N117-7 (CANH) - N117-18 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Blind spot monitor sensor LH*1
      N117-8 (CANH) - N117-19 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 108 to 132 Ω No. 2 CAN junction terminal
      1. *1: w/ Blind Spot Monitor System

      Result

      Result Proceed to
      OK A
      NG (Line to No. 2 CAN junction terminal) B
      NG (Line to No. 2 CAN junction connector) C
      NG (Line to ECU or sensor) D

    Result: 

    REPLACE NO. 8 CAN JUNCTION CONNECTOR 

    Result: 

    REPAIR OR REPLACE CAN MAIN BUS LINES OR CONNECTOR (NO. 2 CAN JUNCTION CONNECTOR - NO. 8 CAN JUNCTION CONNECTOR) 

    Result: 

    See step  5

    Result: 

    See step  4

  4. CHECK FOR SHORT IN CAN BUS LINES (NO. 8 CAN JUNCTION CONNECTOR - NO. 2 CAN JUNCTION TERMINAL) 
    1. Disconnect the N96 No. 2 CAN junction terminal connector.
    2. Measure the resistance according to the value(s) in the table below.
      GTY1086157Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to No. 8 CAN Junction Connector)
      *b to No. 2 CAN Junction Terminal

      Standard Resistance

      Tester Connection Condition Specified Condition
      N117-8 (CANH) - N117-19 (CANL) Cable disconnected from negative (-) auxiliary battery terminal 1 MΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE NO. 2 CAN JUNCTION TERMINAL 

    Result: 

    NG 

    REPAIR OR REPLACE CAN MAIN BUS LINES OR CONNECTOR (NO. 8 CAN JUNCTION CONNECTOR - NO. 2 CAN JUNCTION TERMINAL) 

  5. 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 [08/2021 - 07/2022]

    3. Measure the resistance according to the value(s) in the table below.
      GTY779277Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Component with harness connected
      (Central Gateway ECU (Network Gateway ECU))

      Standard Resistance

      Tester Connection Condition Specified Condition
      F61-23 (CA1H) - F61-8 (CA1L) Cable disconnected from negative (-) auxiliary battery terminal 54 to 69 Ω

      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