LEMON Manuals: Even more car manuals for everyone
Home >> Lexus >> 2011 >> RX 350 AWD >> Repair and Diagnosis (Single Page) >> Accessories & Equipment >> Infotainment >> Navigation System (For HDD) (Diagnostic Codes & Symptom Tests) >> NAVIGATION SYSTEM (for HDD) >> DTC B15D0: MOST Communication Malfunction >> Procedure

DTC B15D0: MOST Communication Malfunction: Procedure

  1. CONFIRM MODEL 
    1. Choose the model to be inspected.

      Result

      Model Proceed to
      for 15 speakers A
      except 15 speakers B

    B → See step   3 

    A: Go to next step 

  2. CONFIRM SYMPTOMS 
    1. Engine switch off.
    2. Turn the engine switch on (ACC) and check if the audio system activates and if the speakers operate.

      HINT: 

      • Choose a source such as radio so that sound can be output from the speakers.
      • If sound from the speakers is low, turn up the volume.

      Result

      Model Proceed to
      The audio system activates when the engine switch is turned on (ACC) but the sound stops being output when the amplifier output exceeds a certain level. A
      Even after the engine switch is turned on (ACC), the audio system does not activate and sound is not output from the speakers. B

      HINT: 

      • If a short occurs in a speaker circuit, the sound from the corresponding speaker will be low or almost impossible to hear. If the volume is turned up in this situation, to prevent excessive current flow due to the short circuit, the stereo component amplifier assembly stops operating when its output exceeds a certain level. When the operation of the stereo component amplifier assembly stops, the navigation system will not function normally. This is because MOST communication will stop due to the shut down of the amplifier causing an error in the MOST network. The stereo component amplifier assembly will start operating again when the engine switch is turned off and back on (ACC) again. However, the amplifier will stop operating again if its output exceeds a certain level.
      • When the stereo component amplifier assembly stops operating and a malfunction occurs in the navigation system due to a short in a speaker circuit, this DTC will be stored. In this case, check each speaker circuit and repair or replace malfunctioning parts, and then recheck for DTCs.

    B → See step   3 

    A → See step   37 

  3. PERFORM MOST LINE CHECK 
    1. Display the "MOST Line Check" screen. Refer to DTC CHECK / CLEAR .
      Fig 1: MOST Line Check Screen
      GTY356172Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Check the result on the "MOST Line Check" screen.

      Result

      Result Proceed to
      "NCON" is displayed for "R-TOUCH". A
      "NCON" is displayed for "AUDIO". B
      "NCON" is displayed for "AMP". C
      "NCON" is displayed for "RSE". (w/ rear seat entertainment system only) D
      "OK" is displayed for all items. E

      HINT: 

      • When "NCON" is displayed for more than 1 item, proceed to the step for the device that has the smallest node position number.
      • The "MOST Line Check" screen can be displayed only when DTC B15D0 is stored.
      TEXT IN ILLUSTRATION

      *1 Node position number for devices that use MOST communication
      *2 Device name
      *3 Result

    B → See step   7 

    C → See step   10 

    D → See step   13 

    E → See step   16 

    A: Go to next step 

  4. CHECK MOST COMMUNICATION CONNECTORS 
    1. Check the MOST communication line connectors.
      1. Check if the MOST communication line connector between the display and navigation module display and remote touch have any connection problems. Refer to ELECTRONIC CIRCUIT INSPECTION PROCEDURE .
    2. Display the "MOST Line Check" screen and check the result. Refer to DTC CHECK / CLEAR .

      Result

      Result Proceed to
      "NCON" is displayed for "R-TOUCH". A
      The screen cannot be changed to the "MOST Line Check" screen. B

      HINT: 

      When the malfunction in the MOST network is repaired, the screen cannot be changed to the "MOST Line Check" screen.

    B → END 

    A: Go to next step 

  5. CHECK HARNESS AND CONNECTOR (WAKE-UP SIGNAL) 
    1. Disconnect the G14 remote touch connector.
      Fig 2: G14 Remote Touch Connector
      GTY348688Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      G14-8 (WUI) - Body ground Engine switch on (ACC) 4.5 V or higher
      TEXT IN ILLUSTRATION

      *1 Front view of wire harness connector
      (to Remote Touch)

    NG → See step   6 

    OK → See step   25 

  6. CHECK HARNESS AND CONNECTOR 
    1. Disconnect the G14 remote touch connector.
      Fig 3: G14 Remote Touch Connector
      GTY348688Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Disconnect the G6 display and navigation module display connector.
      Fig 4: G6 Display And Navigation Module Display Connector
      GTY348506Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      G14-8 (WUI) - G6-8 (WUO) Always Below 1 Ω
      G14-8 (WUI) - Body ground Always 10 kΩ or higher
      TEXT IN ILLUSTRATION

      *1 Front view of wire harness connector
      (to Remote Touch)
      *2 Front view of wire harness connector
      (to Display and Navigation Module Display)

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK → See step   26 

  7. CHECK MOST COMMUNICATION CONNECTORS 
    1. Check the MOST communication line connectors.
      1. Check if the MOST communication line connector between the remote touch and radio receiver assembly have any connection problems. Refer to ELECTRONIC CIRCUIT INSPECTION PROCEDURE .
    2. Display the "MOST Line Check" screen and check the result. Refer to DTC CHECK / CLEAR .

      Result

      Result Proceed to
      "NCON" is displayed for "AUDIO". A
      The screen cannot be changed to the "MOST Line Check" screen. B

      HINT: 

      When the malfunction in the MOST network is repaired, the screen cannot be changed to the "MOST Line Check" screen.

    B → END 

    A: Go to next step 

  8. CHECK HARNESS AND CONNECTOR (WAKE-UP SIGNAL) 
    1. Disconnect the G12 radio receiver assembly connector.
      Fig 5: G12 Radio Receiver Assembly Connector
      GTY349398Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      G12-12 (WUI) - Body ground Engine switch on (ACC) 4.5 V or higher
      TEXT IN ILLUSTRATION

      *1 Front view of wire harness connector
      (to Radio Receiver Assembly)

    NG → See step   9 

    OK → See step   27 

  9. CHECK HARNESS AND CONNECTOR 
    1. Disconnect the G12 radio receiver assembly connector.
      Fig 6: G12 Radio Receiver Assembly Connector
      GTY349398Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Disconnect the G14 remote touch connector.
      Fig 7: G14 Remote Touch Connector
      GTY348687Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      G12-12 (WUI) - G14-4 (WUO) Always Below 1 Ω
      G12-12 (WUI) - Body ground Always 10 kΩ or higher
      TEXT IN ILLUSTRATION

      *1 Front view of wire harness connector
      (to Radio Receiver Assembly)
      *2 Front view of wire harness connector
      (to Remote Touch)

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK → See step   28 

  10. CHECK MOST COMMUNICATION CONNECTORS 
    1. Check the MOST communication line connectors.
      1. Check if the MOST communication line connector between the radio receiver assembly and stereo component amplifier assembly have any connection problems. Refer to ELECTRONIC CIRCUIT INSPECTION PROCEDURE .
    2. Display the "MOST Line Check" screen and check the result. Refer to DTC CHECK / CLEAR .

      Result

      Result Proceed to
      "NCON" is displayed for "AMP". A
      The screen cannot be changed to the "MOST Line Check" screen. B

      HINT: 

      When the malfunction in the MOST network is repaired, the screen cannot be changed to the "MOST Line Check" screen.

    B → END 

    A: Go to next step 

  11. CHECK HARNESS AND CONNECTOR (WAKE-UP SIGNAL) 
    1. Disconnect the O15 stereo component amplifier assembly connector.
      Fig 8: O15 Stereo Component Amplifier Assembly Connector
      GTY353568Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      O15-3 (WUI) - Body ground Engine switch on (ACC) 4.5 V or higher
      TEXT IN ILLUSTRATION

      *1 Front view of wire harness connector
      (to Stereo Component Amplifier Assembly)

    NG → See step   12 

    OK → See step   29 

  12. CHECK HARNESS AND CONNECTOR 
    1. Disconnect the O15 stereo component amplifier assembly connector.
      Fig 9: O15 Stereo Component Amplifier Assembly Connector
      GTY353568Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Disconnect the G12 radio receiver assembly connector.
      Fig 10: G12 Radio Receiver Assembly Connector
      GTY358272Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      O15-3 (WUI) - G12-26 (WUO) Always Below 1 Ω
      O15-3 (WUI) - Body ground Always 10 kΩ or higher
      TEXT IN ILLUSTRATION

      *1 Front view of wire harness connector
      (to Stereo Component Amplifier Assembly)
      *2 Front view of wire harness connector
      (to Radio Receiver Assembly)

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK → See step   30 

  13. CHECK MOST COMMUNICATION CONNECTORS 
    1. Check the MOST communication line connectors.
      1. Check if the MOST communication line connector between the stereo component amplifier assembly and multi-display controller sub-assembly have any connection problems. Refer to ELECTRONIC CIRCUIT INSPECTION PROCEDURE .
    2. Display the "MOST Line Check" screen and check the result. Refer to DTC CHECK / CLEAR .

      Result

      Result Proceed to
      "NCON" is displayed for "RSE". A
      The screen cannot be changed to the "MOST Line Check" screen. B

      HINT: 

      When the malfunction in the MOST network is repaired, the screen cannot be changed to the "MOST Line Check" screen.

    B → END 

    A: Go to next step 

  14. CHECK HARNESS AND CONNECTOR (WAKE-UP SIGNAL) 
    1. Disconnect the G16 multi-display controller sub-assembly connector.
      Fig 11: G16 Multi-Display Controller Sub-Assembly Connector
      GTY359541Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      G16-7 (WUI) - Body ground Engine switch on (ACC) 4.5 V or higher
      TEXT IN ILLUSTRATION

      *1 Front view of wire harness connector
      (to Multi-display Controller Sub-assembly)

    NG → See step   15 

    OK → See step   31 

  15. CHECK HARNESS AND CONNECTOR 
    1. Disconnect the G16 multi-display controller sub-assembly connector.
      Fig 12: G16 Multi-Display Controller Sub-Assembly Connector
      GTY359541Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Disconnect the O15 stereo component amplifier assembly connector.
      Fig 13: O15 Stereo Component Amplifier Assembly Connector
      GTY353567Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      G16-7 (WUI) - O15-9 (WUO) Always Below 1 Ω
      G16-7 (WUI) - Body ground Always 10 kΩ or higher
      TEXT IN ILLUSTRATION

      *1 Front view of wire harness connector
      (to Multi-display Controller Sub-assembly)
      *2 Front view of wire harness connector
      (to Stereo Component Amplifier Assembly)

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK → See step   32 

  16. CHECK HARNESS AND CONNECTOR 
    1. Disconnect the G6 display and navigation module display connector.
      Fig 14: G6 Display And Navigation Module Display Connector
      GTY348505Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Disconnect the G14 remote touch connector.
      Fig 15: G14 Remote Touch Connector
      GTY348682Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      G6-3 (MO+) - G14-6 (MI+) Always Below 1 Ω
      G6-7 (MO-) - G14-5 (MI-) Always Below 1 Ω
      G6-6 (SLDO) - G14-7 (SLDI) Always Below 1 Ω
      G6-8 (WUO) - G14-8 (WUI) Always Below 1 Ω
      G6-3 (MO+) - Body ground Always 10 kΩ or higher
      G6-7 (MO-) - Body ground Always 10 kΩ or higher
      G6-6 (SLDO) - Body ground Always 10 kΩ or higher
      G6-8 (WUO) - Body ground Always 10 kΩ or higher
      TEXT IN ILLUSTRATION

      *1 Front view of wire harness connector
      (to Display and Navigation Module Display)
      *2 Front view of wire harness connector
      (to Remote Touch)

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  17. CHECK HARNESS AND CONNECTOR 
    1. Disconnect the G14 remote touch connector.
      Fig 16: G14 Remote Touch Connector
      GTY348681Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Disconnect the G12 radio receiver assembly connector.
      Fig 17: G12 Radio Receiver Assembly Connector
      GTY349397Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      G14-1 (MO+) - G12-9 (MI+) Always Below 1 Ω
      G14-2 (MO-) - G12-23 (MI-) Always Below 1 Ω
      G14-3 (SLDO) - G12-10 (SLDI) Always Below 1 Ω
      G14-4 (WUO) - G12-12 (WUI) Always Below 1 Ω
      G14-1 (MO+) - Body ground Always 10 kΩ or higher
      G14-2 (MO-) - Body ground Always 10 kΩ or higher
      G14-3 (SLDO) - Body ground Always 10 kΩ or higher
      G14-4 (WUO) - Body ground Always 10 kΩ or higher
      TEXT IN ILLUSTRATION

      *1 Front view of wire harness connector
      (to Remote Touch)
      *2 Front view of wire harness connector
      (to Radio Receiver Assembly)

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  18. CHECK HARNESS AND CONNECTOR 
    1. Disconnect the G12 radio receiver assembly connector.
      Fig 18: G12 Radio Receiver Assembly Connector
      GTY349395Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Disconnect the O15 stereo component amplifier assembly connector.
      Fig 19: O15 Stereo Component Amplifier Assembly Connector
      GTY353570Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      G12-11 (MO+) - O15-4 (MI+) Always Below 1 Ω
      G12-25 (MO-) - O15-10 (MI-) Always Below 1 Ω
      G12-24 (SLDI) - O15-5 (SLDI) Always Below 1 Ω
      G12-26 (WUO) - O15-3 (WUI) Always Below 1 Ω
      G12-11 (MO+) - Body ground Always 10 kΩ or higher
      G12-25 (MO-) - Body ground Always 10 kΩ or higher
      G12-24 (SLDI) - Body ground Always 10 kΩ or higher
      G12-26 (WUO) - Body ground Always 10 kΩ or higher
      TEXT IN ILLUSTRATION

      *1 Front view of wire harness connector
      (to Radio Receiver Assembly)
      *2 Front view of wire harness connector
      (to Stereo Component Amplifier Assembly)

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  19. CONFIRM MODEL 
    1. Choose the model to be inspected.

      Result

      Result Proceed to
      w/o Rear Seat Entertainment System A
      w/ Rear Seat Entertainment System B

    B → See step   22 

    A: Go to next step 

  20. CHECK HARNESS AND CONNECTOR 
    1. Disconnect the O15 stereo component amplifier assembly connector.
      Fig 20: O15 Stereo Component Amplifier Assembly Connector
      GTY353569Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Disconnect the G6 display and navigation module display connector.
      Fig 21: G6 Display And Navigation Module Display Connector
      GTY358138Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      O15-6 (MO+) - G6-1 (MI+) Always Below 1 Ω
      O15-12 (MO-) - G6-5 (MI-) Always Below 1 Ω
      O15-11 (SLDO) - G6-2 (SLDI) Always Below 1 Ω
      O15-6 (MO+) - Body ground Always 10 kΩ or higher
      O15-12 (MO-) - Body ground Always 10 kΩ or higher
      O15-11 (SLDO) - Body ground Always 10 kΩ or higher
      TEXT IN ILLUSTRATION

      *1 Front view of wire harness connector
      (to Stereo Component Amplifier Assembly)
      *2 Front view of wire harness connector
      (to Display and Navigation Module Display)

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  21. CHECK DTC 
    1. Clear the DTCs. Refer to DTC CHECK / CLEAR .
    2. Recheck for DTCs and check if the same DTC is output again.

      Result

      Result Proceed to
      No DTCs are output. A
      DTC is output. B

    B → See step   33 

    A → See step   35 

  22. CHECK HARNESS AND CONNECTOR 
    1. Disconnect the O15 stereo component amplifier assembly connector.
      Fig 22: O15 Stereo Component Amplifier Assembly Connector
      GTY353557Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Disconnect the G16 multi-display controller sub-assembly connector.
      Fig 23: G16 Multi-Display Controller Sub-Assembly Connector
      GTY357627Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      O15-6 (MO+) - G16-1 (MI+) Always Below 1 Ω
      O15-12 (MO-) - G16-2 (MI-) Always Below 1 Ω
      O15-11 (SLDO) - G16-3 (SLDI) Always Below 1 Ω
      O15-9 (WUO) - G16-7 (WUI) Always Below 1 Ω
      O15-6 (MO+) - Body ground Always 10 kΩ or higher
      O15-12 (MO-) - Body ground Always 10 kΩ or higher
      O15-11 (SLDO) - Body ground Always 10 kΩ or higher
      O15-9 (WUO) - Body ground Always 10 kΩ or higher
      TEXT IN ILLUSTRATION

      *1 Front view of wire harness connector
      (to Stereo Component Amplifier Assembly)
      *2 Front view of wire harness connector
      (to Multi-display Controller Sub-assembly)

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  23. CHECK HARNESS AND CONNECTOR 
    1. Disconnect the G16 multi-display controller sub-assembly connector.
      Fig 24: Identifying G16 Multi-Display Controller Sub-Assembly Connector
      GTY283723Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    2. Disconnect the G6 display and navigation module display connector.
      Fig 25: G6 Display And Navigation Module Display Connector
      GTY358138Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      G16-6 (MO+) - G6-1 (MI+) Always Below 1 Ω
      G16-5 (MO-) - G6-5 (MI-) Always Below 1 Ω
      G16-4 (SLDO) - G6-2 (SLDI) Always Below 1 Ω
      G16-6 (MO+) - Body ground Always 10 kΩ or higher
      G16-5 (MO-) - Body ground Always 10 kΩ or higher
      G16-4 (SLDO) - Body ground Always 10 kΩ or higher
      TEXT IN ILLUSTRATION

      *1 Front view of wire harness connector
      (to Multi-display Controller Sub-assembly)
      *2 Front view of wire harness connector
      (to Display and Navigation Module Display)

    NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

    OK: Go to next step 

  24. CHECK DTC 
    1. Clear the DTCs. Refer to DTC CHECK / CLEAR .
    2. Recheck for DTCs and check if the same DTC is output again.

      Result

      Result Proceed to
      No DTCs are output. A
      DTC is output. B

    B → See step   34 

    A → See step   36 

  25. REPLACE REMOTE OPERATION BOARD. Refer to  REMOVAL 
  26. REPLACE DISPLAY AND NAVIGATION MODULE DISPLAY. Refer to  REMOVAL 
  27. REPLACE RADIO RECEIVER ASSEMBLY. Refer to  REMOVAL 
  28. REPLACE REMOTE OPERATION BOARD. Refer to  REMOVAL 
  29. REPLACE STEREO COMPONENT AMPLIFIER ASSEMBLY. Refer to  REMOVAL 
  30. REPLACE RADIO RECEIVER ASSEMBLY. Refer to  REMOVAL 
  31. REPLACE MULTI-DISPLAY CONTROLLER SUB-ASSEMBLY. Refer to  REMOVAL 
  32. REPLACE STEREO COMPONENT AMPLIFIER ASSEMBLY. Refer to  REMOVAL 
  33. REPLACE DISPLAY AND NAVIGATION MODULE DISPLAY. Refer to  REMOVAL 
  34. REPLACE DISPLAY AND NAVIGATION MODULE DISPLAY. Refer to  REMOVAL 
  35. USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING 
  36. USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING 
  37. GO TO AUDIO AND VISUAL SYSTEM (w/ Navigation System). Refer to  Speaker Circuit 
scientia non olet · About LEMON Manuals