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DTC U0208: Lost Communication with "Seat Control Module A" [09/2014 - 11/2017]: Procedure

  1. RECONFIRM DTC OUTPUT 

    Body Electrical > Main Body > Trouble Codes 

    1. Reconfirm DTCs.

      HINT: 

      If DTC U1002 is output from Main Body of the main body ECU (multiplex network body ECU), this indicates a sub bus 1 malfunction. Troubleshoot for DTC U1002 and check for malfunctions in sub bus 1.

      Result

      Result Proceed to
      DTC U1002 is not output from main body ECU (multiplex network body ECU) (Techstream display: Main Body) A
      DTC U1002 is output from main body ECU (multiplex network body ECU) (Techstream display: Main Body) B

    Result: 

    B 

    GO TO DIAGNOSTIC PROCEDURE INDICATED BY OUTPUT DTC. Refer to  DTC U1002: Lost Communication with Gateway Module (Main Body ECU) [09/2014 - 11/2017] 

    Result: 

    A 

    See step  2

  2. CHECK FOR OPEN IN SUB BUS 1 LINES (POSITION CONTROL ECU AND SWITCH ASSEMBLY LH BRANCH LINE) 
    1. Disconnect the cable from the negative (-) battery terminal.
    2. Disconnect the b5 position control ECU and switch assembly LH connector.
      GTY509588Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to Position Control ECU and Switch Assembly LH)
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      b5-8 (CANP) - b5-7 (CANN) Cable disconnected from negative (-) battery terminal 54 to 69 Ω

      Result

      Result
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE CAN BRANCH LINES OR CONNECTOR (POSITION CONTROL ECU AND SWITCH ASSEMBLY LH BRANCH LINES) 

    Result: 

    OK 

    See step  3

  3. CHECK HARNESS AND CONNECTOR (POWER SOURCE CIRCUIT) 
    1. Disconnect the b4 position control ECU and switch assembly LH connector.
      GTY513507Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to Position Control ECU and Switch Assembly LH)
    2. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      b4-2 (GND) - Body ground Cable disconnected from negative (-) battery terminal Below 1 Ω
    3. Reconnect the cable to the negative (-) battery terminal.
    4. Measure the voltage according to the value(s) in the table below.
      GTY519305Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Front view of wire harness connector
      (to Position Control ECU and Switch Assembly LH)

      Standard Voltage

      Tester Connection Condition Specified Condition
      b4-7 (+B) - Body ground Always 11 to 14 V
      b5-3 (IG) - Body ground Engine switch on (IG) 11 to 14 V
      b5-12 (SYSB) - Body ground Always 11 to 14 V

      Result

      Result
      OK
      NG

    Result: 

    OK 

    REPLACE POSITION CONTROL ECU AND SWITCH ASSEMBLY LH. Refer to  REMOVAL [09/2014 - ] 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR (POWER SOURCE CIRCUIT) 

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