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Driver Side Switch Module LIN Communication Malfunction [09/2013 - ]: Procedure

  1. CLEAR DTC 
    1. Clear the DTC. Refer to DTC CHECK / CLEAR [09/2013 - ] .

    NEXT: Go to next step 

  2. CHECK FOR DTC 
    1. Recheck for DTC. Refer to DTC CHECK / CLEAR [09/2013 - ] .
      RESULT

      Result Proceed to
      DTC U1127, U1128* and U1129* are output A
      DTC U1127, U1128* or U1129* is output B
      No DTC is output C

      HINT: 

      *: w/ Climate Control Seat System

    B → See step   10 

    C → See step   11 

    A: Go to next step 

  3. CHECK HARNESS AND CONNECTOR (OUTER MIRROR SWITCH - NO. 1 CONSOLE SWITCH) 
    1. Disconnect the L6 and L75 switch connectors.
      GTY409521Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the resistance and voltage according to the value(s) in the table below.

      Standard resistance

      Tester Connection Condition Specified Condition
      L6-7 (MPX) - L75-3 (MPX) Always Below 1 Ω
      L6-7 (MPX) or L75-3 (MPX) - Body ground Always 10 kΩ or higher

      Standard voltage

      Tester Connection Condition Specified Condition
      L6-7 (MPX) or L75-3 (MPX) - Body ground Always Below 1 V

    NG → See step   4 

    OK → See step   12 

  4. CLEAR DTC 
    1. Reconnect the L6 switch connector.
    2. Clear the DTC. Refer to DTC CHECK / CLEAR [09/2013 - ] .

    NEXT: Go to next step 

  5. CHECK FOR DTC 
    1. Disconnect the L75 switch connector.
    2. Recheck for DTC. Refer to DTC CHECK / CLEAR [09/2013 - ] .
      RESULT

      Result Proceed to
      DTC U1127, U1128* and U1129* are output A
      DTC U1127 is output (w/o Rear Entertainment System) B
      DTC U1127 is output (w/ Rear Entertainment System) C

      HINT: 

      *: w/ Climate Control Seat System

    B → See step   13 

    C → See step   16 

    A: Go to next step 

  6. CLEAR DTC 
    1. Reconnect the L75 switch connector.
    2. Clear the DTC. Refer to DTC CHECK / CLEAR [09/2013 - ] .

    NEXT: Go to next step 

  7. CHECK FOR DTC 
    1. Disconnect the e4 ECU connector.
    2. Recheck for DTC. Refer to DTC CHECK / CLEAR [09/2013 - ] .
      RESULT

      Result Proceed to
      DTC U1127, U1128* and U1129* are output A
      DTC U1128* is output B

      HINT: 

      *: w/ Climate Control Seat System

    B → See step   14 

    A: Go to next step 

  8. CLEAR DTC 
    1. Reconnect the e4 ECU connector.
    2. Clear the DTC. Refer to DTC CHECK / CLEAR [09/2013 - ] .

    NEXT: Go to next step 

  9. CHECK FOR DTC 
    1. Disconnect the e34 ECU connector.
    2. Recheck for DTC. Refer to DTC CHECK / CLEAR [09/2013 - ] .
      RESULT

      Result Proceed to
      DTC U1127, U1128* and U1129* are output A
      DTC U1129* is output B

      HINT: 

      *: w/ Climate Control Seat System

    B → See step   15 

    A → REPAIR OR REPLACE HARNESS OR CONNECTOR 

  10. Go to DTC CHART. Refer to  DIAGNOSTIC TROUBLE CODE CHART [09/2013 - ] 
  11. USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [09/2013 - ] 
  12. REPLACE OUTER MIRROR SWITCH. Refer to  REMOVAL [09/2013 - ] 
  13. REPLACE NO. 1 CONSOLE SWITCH. Refer to  DISASSEMBLY [09/2013 - ] 
  14. REPLACE FRONT SEAT CLIMATE CONTROL ECU RH. Refer to  DISASSEMBLY [09/2013 - ] 
  15. REPLACE FRONT SEAT CLIMATE CONTROL ECU LH. Refer to  DISASSEMBLY [09/2013 - ] 
  16. REPLACE NO. 1 CONSOLE SWITCH. Refer to  DISASSEMBLY [09/2013 - ] 
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