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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 Line for Short to GND [10/2018 - 10/2019] >> Procedure

Check Bus 3 Line for Short to GND [10/2018 - 10/2019]: Procedure

WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2024 Lexus UX 250h, 2023 Lexus UX 250h, 2022 Lexus UX 250h, 2021 Lexus UX 250h, and 2020 Lexus UX 250h. However, it is still accessible from the selected car via links, so may be relevant.
  1. CHECK FOR SHORT TO GND IN CAN BUS LINE (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.
      GTY820355Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *1 DLC3 - -
      *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) - F58-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Central gateway ECU (network gateway ECU)
      F91-12 (CANL) - F58-4 (CG)
      F91-2 (CANH) - F58-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Central gateway ECU (network gateway ECU)
      F91-13 (CANL) - F58-4 (CG)

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    See step  4

    Result: 

    OK 

    See step  2

  2. CHECK FOR SHORT TO GND IN CAN BUS LINE (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.
      GTY820349Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *1 DLC3 - -
      *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) - F58-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Radio receiver assembly
      F92-19 (CANL) - F58-4 (CG)
      F92-9 (CANH) - F58-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher DCM (telematics transceiver)*1
      F92-20 (CANL) - F58-4 (CG)
      F92-10 (CANH) - F58-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher Stereo component equalizer assembly*2
      F92-21 (CANL) - F58-4 (CG)
      1. *1: for Lexus Enform
      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 TO GND IN CAN BUS LINE (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 bus line shorted to GND is connected.

      Refer to TERMINALS OF ECU [10/2018 - 10/2019]

    3. Measure the resistance according to the value(s) in the table below.
      GTY786217Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *1 DLC3 - -
      *a Component with harness connected
      (Central Gateway ECU (Network Gateway ECU))
      - -

      Standard Resistance

      Tester Connection Condition Specified Condition
      F61-6 (CA3H) - F58-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher
      F61-21 (CA3L) - F58-4 (CG)

      HINT: 

      • If the resistance changes to 200 Ω or higher 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 to ground 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 TO GND IN CAN BUS LINE (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.
      GTY820355Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *1 DLC3 - -
      *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) - F58-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher
      F91-12 (CANL) - F58-4 (CG)
      F91-2 (CANH) - F58-4 (CG) Cable disconnected from negative (-) auxiliary battery terminal 200 Ω or higher
      F91-13 (CANL) - F58-4 (CG)

      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 LINE OR CONNECTOR (NO. 5 CAN JUNCTION CONNECTOR - CENTRAL GATEWAY ECU (NETWORK GATEWAY ECU))