LEMON Manuals: Even more car manuals for everyone
Home >> Lexus >> 2021 >> LC 500 2D Coupe >> Repair and Diagnosis >> Accessories & Equipment >> Communication Devices >> Can Communication System - Circuit Tests (Coupe) (1 Of 6) & Diagnostic Codes >> Can Communication System >> Shift Control ECU Communication Stop Mode [05/2023 - ] >> Procedure

Shift Control ECU Communication Stop Mode [05/2023 - ]: Procedure

  1. CHECK FOR OPEN IN CAN BUS WIRE (SHIFT CONTROL ECU BRANCH WIRE) 
    1. Disconnect the cable from the negative (-) battery terminal.
      NOTE:

      The vehicle is equipped with a integration control supply. Therefore, ensure there is no power being supplied to the vehicle when disconnecting or reconnecting the connector of the shift control ECU and when removing or installing the shift control ECU.

      Refer to REMOVAL [05/2023 - ]

    2. Disconnect the shift control ECU connector.
      GTY804810Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to Shift Control ECU)
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      P74-9 (CA1H) - P74-8 (CA1L) Cable disconnected from negative (-) battery terminal 54 to 69 Ω

      Result

      Result
      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. Disconnect the shift control ECU connector.
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      P74-1 (E1) - Body ground Cable disconnected from negative (-) battery terminal Below 1 Ω
      P74-11 (EC) - Body ground Cable disconnected from negative (-) battery terminal Below 1 Ω
      P75-4 (E03) - Body ground Cable disconnected from negative (-) battery terminal Below 1 Ω
      P75-5 (E02) - Body ground Cable disconnected from negative (-) battery terminal Below 1 Ω
      P75-6 (E01) - Body ground Cable disconnected from negative (-) battery terminal Below 1 Ω
      P75-17 (E12) - Body ground Cable disconnected from negative (-) battery terminal Below 1 Ω
      GTY837968Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to Shift Control ECU)
    3. Reconnect the cable to the negative (-) battery terminal.
      NOTE:

      When disconnecting the cable, some systems need to be initialized after the cable is reconnected.

      Refer to WORK PROCEDURE [05/2023 - ]

    4. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      P75-1 (BATT) - Body ground Always 8 to 15.4 V
      P74-10 (BUB) - Body ground 5 seconds after engine switch on (IG)* 8 to 15.4 V
      P74-18 (ACC) - Body ground Engine switch on (ACC) 8 to 15.4 V
      Engine switch off Below 1 V
      P74-27 (IG2) - Body ground Engine switch on (IG) 8 to 15.4 V
      Engine switch off Below 1 V

      *: Power is supplied from the integration control supply for only 5 seconds after the engine switch is turned on (IG). Therefore, measure the voltage during that time.

      Result

      Result
      OK
      NG

    Result: 

    OK 

    REPLACE SHIFT CONTROL ECU. Refer to  REMOVAL [05/2023 - ] 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

scientia non olet · About LEMON Manuals