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Home >> Lexus >> 2007 >> SC 430 >> Repair and Diagnosis >> Body & Frame >> Exterior/Interior Trim >> Multiplex Communication >> Multiplex Communication System >> DTC B1273 Sliding Roof ECU Communication Stop >> Inspection Procedure
July 1: So it begins. Don't worry, this is not in the correct legal jurisdiction!

Inspection Procedure

  1. CHECK LUGGAGE DOOR OPENING SWITCH ASSEMBLY (OPERATION) 
    1. Check that the luggage door opening switch can operate the retractable hardtop normally.

      OK: Luggage door opening switch can operate retractable hardtop normally. 

    OK: REPLACE SLIDING ROOF CONTROL ECU 

    NG: Go to next step. 

  2. CHECK WIRE HARNESS (SLIDING ROOF CONTROL ECU - BATTERY AND BODY GROUND) 
    1. Disconnect the S18 and S19 ECU connectors.
      Fig 1: Identifying S18 And S19 ECU Connectors
      G05294489Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the resistance and voltage of the wire harness side connectors.

      Standard voltage 

      VOLTAGE SPECIFICATION

      Tester Connection Specified Condition
      S19-8 (CPUB) - Body ground 10 to 14 V

      Standard resistance 

      RESISTANCE SPECIFICATION

      Tester Connection Specified Condition
      S18-5 (E5) - Body ground Below 1 Ω
      S18-6 (E1) - Body ground Below 1 Ω
      S19-9 (E2) - Body ground Below 1 Ω
      S19-10 (E3) - Body ground Below 1 Ω
      S19-11 (E4) - Body ground Below 1 Ω

    NG: REPAIR OR REPLACE HARNESS AND CONNECTOR 

    OK: Go to next step. 

  3. CHECK RESISTANCE OF COMMUNICATION LINE 
    1. Disconnect the P9, P23 and S18 ECU connectors.
      Fig 2: Identifying P9, P23 And S18 ECU Connectors
      G05294490Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the resistance of the wire harness side connectors.

      Standard resistance 

      RESISTANCE SPECIFICATION

      Tester Connection Specified Condition
      S18-7 (MPX1) - P9-30 (MPX2) Below 1 Ω
      S18-1 (MPX2) - P23-10 (MPX1) Below 1 Ω

      Result 

      RESULT CHART

      Result Proceed to
      Both are OK A
      One is OK B
      Both are NG C

    B: REPLACE SLIDING ROOF CONTROL ECU AND REPAIR OR REPLACE HARNESS AND CONNECTOR 

    C: REPAIR OR REPLACE HARNESS AND CONNECTOR 

    A: REPLACE SLIDING ROOF CONTROL ECU