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DTC B15D0: MOST Communication Malfunction [10/2015 - 12/2017]: Procedure

  1. CHECK RESULT OF SYSTEM CHECK MODE 
    1. Enter the "System Check Mode" screen. Refer to Check DTC (Check Using System Check Mode Screen) in DTC Check / Clear.
      GTY632229Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Node position number for devices connected to the MOST network
      *b Device Name
      *c Result

      Refer to DTC CHECK / CLEAR [10/2015 - 08/2019]

    2. Check the result on the "System Check Mode" screen.

      Result

      Result Proceed to
      "MOST" is displayed for "EMV-M". A
      "DETAIL" is displayed for "EMV-M". B

    Result: 

    B 

    USE SIMULATION METHOD TO CHECK. Refer to  HOW TO PROCEED WITH TROUBLESHOOTING [10/2015 - 08/2016]  , or refer to  HOW TO PROCEED WITH TROUBLESHOOTING [08/2016 - 12/2017] 

    Result: 

    A 

    See step  2

  2. PERFORM MOST LINE CHECK 
    1. Enter the "MOST Line Check" screen. Refer to Check DTC (Check Using System Check Mode Screen) in DTC Check / Clear.
      GTY658789Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
      *a Node position number for devices connected to the MOST network
      *b Device Name
      *c Result

      Refer to DTC CHECK / CLEAR [10/2015 - 08/2019]

    2. Check if the MOST communication lines connectors and terminals of the radio receiver assembly, stereo component amplifier assembly and multi-display controller sub-assembly* for connection problems.
      1. *: w/ Rear Seat Entertainment System
    3. Check the result on the "MOST Line Check" screen.

      Result

      Result Proceed to
      "OK" is displayed for all items.
      (w/o Rear Seat Entertainment System)      		 A
      "OK" is displayed for all items.
      (w/ Rear Seat Entertainment System)      		 B
      "NCON" is displayed for "AMP".
      (w/o Rear Seat Entertainment System)      		 C
      "NCON" is displayed for "REAR".
      (w/ Rear Seat Entertainment System)      		 D
      "NCON" is displayed for "REAR" and "AMP".
      (w/ Rear Seat Entertainment System)      		 E
      "NCON" is displayed for "EMV-M". F

      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.

    Result: 

    B 

    See step  5

    Result: 

    C 

    See step  10

    Result: 

    D 

    See step  12

    Result: 

    E 

    See step  14

    Result: 

    F 

    REPLACE RADIO RECEIVER ASSEMBLY. Refer to  REMOVAL [10/2015 - 08/2016]  , or refer to  REMOVAL [08/2016 - 03/2018] 

    Result: 

    A 

    See step  3

  3. CHECK HARNESS AND CONNECTOR (RADIO RECEIVER ASSEMBLY - STEREO COMPONENT AMPLIFIER ASSEMBLY) 
    1. Disconnect the J122 radio receiver assembly connector.
    2. Disconnect the J123 stereo component amplifier assembly connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      J122-2 (MI+) - J123-5 (MO+) Always Below 1 Ω
      J122-3 (MI-) - J123-6 (MO-) Always Below 1 Ω
      J122-4 (SLDI) - J123-7 (SLDO) Always Below 1 Ω
      J122-5 (MO+) - J123-2 (MI+) Always Below 1 Ω
      J122-6 (MO-) - J123-3 (MI-) Always Below 1 Ω
      J122-7 (SLDO) - J123-4 (SLDI) Always Below 1 Ω
      J122-2 (MI+) or J123-5 (MO+) - Body ground Always 10 kΩ or higher
      J122-3 (MI-) or J123-6 (MO-) - Body ground Always 10 kΩ or higher
      J122-4 (SLDI) or J123-7 (SLDO) - Body ground Always 10 kΩ or higher
      J122-5 (MO+) or J123-2 (MI+) - Body ground Always 10 kΩ or higher
      J122-6 (MO-) or J123-3 (MI-) - Body ground Always 10 kΩ or higher
      J122-7 (SLDO) or J123-4 (SLDI) - Body ground Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  4

  4. REPLACE STEREO COMPONENT AMPLIFIER ASSEMBLY 
    1. Replace the stereo component amplifier assembly with a new or known good one.

      Refer to REMOVAL [10/2015 - 03/2018]

    2. Clear the DTCs.

      Refer to DTC CHECK / CLEAR [10/2015 - 08/2019]

      Body Electrical > Navigation System > Clear DTCs 

    3. Recheck for DTCs and check that no DTCs are output.

      Body Electrical > Navigation System > Trouble Codes 

      OK

      No DTCs are output.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    END 

    Result: 

    NG 

    REPLACE RADIO RECEIVER ASSEMBLY. Refer to  REMOVAL [10/2015 - 08/2016]  , or refer to  REMOVAL [08/2016 - 03/2018] 

  5. CHECK HARNESS AND CONNECTOR (RADIO RECEIVER ASSEMBLY - STEREO COMPONENT AMPLIFIER ASSEMBLY) 
    1. Disconnect the J122 radio receiver assembly connector.
    2. Disconnect the J123 stereo component amplifier assembly connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      J122-5 (MO+) - J123-2 (MI+) Always Below 1 Ω
      J122-6 (MO-) - J123-3 (MI-) Always Below 1 Ω
      J122-7 (SLDO) - J123-4 (SLDI) Always Below 1 Ω
      J122-5 (MO+) or J123-2 (MI+) - Body ground Always 10 kΩ or higher
      J122-6 (MO-) or J123-3 (MI-) - Body ground Always 10 kΩ or higher
      J122-7 (SLDO) or J123-4 (SLDI) - Body ground Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  6

  6. CHECK HARNESS AND CONNECTOR (STEREO COMPONENT AMPLIFIER ASSEMBLY - MULTI-DISPLAY CONTROLLER SUB-ASSEMBLY) 
    1. Disconnect the J123 stereo component amplifier assembly connector.
    2. Disconnect the R45 multi-display controller sub-assembly connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      J123-5 (MO+) - R45-2 (MI+) Always Below 1 Ω
      J123-6 (MO-) - R45-3 (MI-) Always Below 1 Ω
      J123-7 (SLDO) - R45-4 (SLDI) Always Below 1 Ω
      J123-5 (MO+) or R45-2 (MI+) - Body ground Always 10 kΩ or higher
      J123-6 (MO-) or R45-3 (MI-) - Body ground Always 10 kΩ or higher
      J123-7 (SLDO) or R45-4 (SLDI) - Body ground Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  7

  7. CHECK HARNESS AND CONNECTOR (RADIO RECEIVER ASSEMBLY - MULTI-DISPLAY CONTROLLER SUB-ASSEMBLY) 
    1. Disconnect the J122 radio receiver assembly connector.
    2. Disconnect the R45 multi-display controller sub-assembly connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      J122-2 (MI+) - R45-5 (MO+) Always Below 1 Ω
      J122-3 (MI-) - R45-6 (MO-) Always Below 1 Ω
      J122-4 (SLDI) - R45-7 (SLDO) Always Below 1 Ω
      J122-2 (MI+) or R45-5 (MO+) - Body ground Always 10 kΩ or higher
      J122-3 (MI-) or R45-6 (MO-) - Body ground Always 10 kΩ or higher
      J122-4 (SLDI) or R45-7 (SLDO) - Body ground Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  8

  8. REPLACE MULTI-DISPLAY CONTROLLER SUB-ASSEMBLY 
    1. Replace the multi-display controller sub-assembly with a new or known good one.

      Refer to REMOVAL [10/2015 - 08/2016] , or refer to REMOVAL [08/2016 - 12/2017]

    2. Clear the DTCs.

      Refer to DTC CHECK / CLEAR [10/2015 - 08/2019]

      Body Electrical > Navigation System > Clear DTCs 

    3. Recheck for DTCs and check that no DTCs are output.

      Body Electrical > Navigation System > Trouble Codes 

      OK

      No DTCs are output.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    END 

    Result: 

    NG 

    See step  9

  9. REPLACE STEREO COMPONENT AMPLIFIER ASSEMBLY 
    1. Replace the stereo component amplifier assembly with a new or known good one.

      Refer to REMOVAL [10/2015 - 03/2018]

    2. Clear the DTCs.

      Refer to DTC CHECK / CLEAR [10/2015 - 08/2019]

      Body Electrical > Navigation System > Clear DTCs 

    3. Recheck for DTCs and check that no DTCs are output.

      Body Electrical > Navigation System > Trouble Codes 

      OK

      No DTCs are output.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    END 

    Result: 

    NG 

    REPLACE RADIO RECEIVER ASSEMBLY. Refer to  REMOVAL [10/2015 - 08/2016]  , or refer to  REMOVAL [08/2016 - 03/2018] 

  10. CHECK HARNESS AND CONNECTOR (WAKE-UP SIGNAL) 
    1. Disconnect the J123 stereo component amplifier assembly connector.
    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      J123-8 (WUI) - Body ground Power switch on (ACC) 4.5 V or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE STEREO COMPONENT AMPLIFIER ASSEMBLY. Refer to  REMOVAL [10/2015 - 03/2018] 

    Result: 

    NG 

    See step  11

  11. CHECK HARNESS AND CONNECTOR (RADIO RECEIVER ASSEMBLY - STEREO COMPONENT AMPLIFIER ASSEMBLY) 
    1. Disconnect the J122 radio receiver assembly connector.
    2. Disconnect the J123 stereo component amplifier assembly connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      J122-1 (WUO) - J123-8 (WUI) Always Below 1 Ω
      J122-1 (WUO) or J123-8 (WUI) - Body ground Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE RADIO RECEIVER ASSEMBLY. Refer to  REMOVAL [10/2015 - 08/2016]  , or refer to  REMOVAL [08/2016 - 03/2018] 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

  12. CHECK HARNESS AND CONNECTOR (WAKE-UP SIGNAL) 
    1. Disconnect the R45 multi-display controller sub-assembly connector.
    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      R45-8 (WUI) - Body ground Power switch on (ACC) 4.5 V or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE MULTI-DISPLAY CONTROLLER SUB-ASSEMBLY. Refer to  REMOVAL [10/2015 - 08/2016]  , or refer to  REMOVAL [08/2016 - 12/2017] 

    Result: 

    NG 

    See step  13

  13. CHECK HARNESS AND CONNECTOR (STEREO COMPONENT AMPLIFIER ASSEMBLY - MULTI-DISPLAY CONTROLLER SUB-ASSEMBLY) 
    1. Disconnect the J123 stereo component amplifier assembly connector.
    2. Disconnect the R45 multi-display controller sub-assembly connector.
    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance

      Tester Connection Condition Specified Condition
      J123-1 (WUO) - R45-8 (WUI) Always Below 1 Ω
      J123-1 (WUO) or R45-8 (WUI) - Body ground Always 10 kΩ or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE STEREO COMPONENT AMPLIFIER ASSEMBLY. Refer to  REMOVAL [10/2015 - 03/2018] 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

  14. CHECK HARNESS AND CONNECTOR (WAKE-UP SIGNAL) 
    1. Disconnect the J123 stereo component amplifier assembly connector.
    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      J123-8 (WUI) - Body ground Power switch on (ACC) 4.5 V or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

    Result: 

    OK 

    See step  15

  15. REPLACE STEREO COMPONENT AMPLIFIER ASSEMBLY 
    1. Replace the stereo component amplifier assembly with a new or known good one.

      Refer to REMOVAL [10/2015 - 03/2018]

    2. Clear the DTCs.

      Refer to DTC CHECK / CLEAR [10/2015 - 08/2019]

      Body Electrical > Navigation System > Clear DTCs 

    3. Recheck for DTCs and check that no DTCs are output.

      Body Electrical > Navigation System > Trouble Codes 

      OK

      No DTCs are output.

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    END 

    Result: 

    NG 

    See step  16

  16. CHECK HARNESS AND CONNECTOR (WAKE-UP SIGNAL) 
    1. Disconnect the R45 multi-display controller sub-assembly connector.
    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage

      Tester Connection Condition Specified Condition
      R45-8 (WUI) - Body ground Power switch on (ACC) 4.5 V or higher

      Result

      Proceed to
      OK
      NG

    Result: 

    OK 

    REPLACE MULTI-DISPLAY CONTROLLER SUB-ASSEMBLY. Refer to  REMOVAL [10/2015 - 08/2016]  , or refer to  REMOVAL [08/2016 - 12/2017] 

    Result: 

    NG 

    REPAIR OR REPLACE HARNESS OR CONNECTOR 

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