DTC B15D0: MOST Communication Malfunction [12/2017 - 08/2019]: Procedure

1. Enter the "System Check Mode" screen. Refer to Check DTC (Check Using System Check Mode Screen) in DTC Check / Clear.

   Courtesy 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 [12/2017 - 03/2018]  , or refer to  HOW TO PROCEED WITH TROUBLESHOOTING [03/2018 - 08/2019] 

Result: 

A 

See step  2

1. Enter the "MOST Line Check" screen. Refer to Check DTC (Check Using System Check Mode Screen) in DTC Check / Clear.

   Courtesy 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 and stereo component amplifier assembly for connection problems.
3. Check the result on the "MOST Line Check" screen.

   Result

   Result	Proceed to
   "OK" is displayed for all items.	A
   "NCON" is displayed for "AMP".	B
   "NCON" is displayed for "EMV-M".	C

   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 

REPLACE RADIO RECEIVER ASSEMBLY. Refer to  REMOVAL [08/2016 - 03/2018]  , or refer to  REMOVAL [03/2018 - 08/2019] 

Result: 

A 

See step  3

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

1. Replace the stereo component amplifier assembly with a new or known good one.

   Refer to REMOVAL [10/2015 - 03/2018] , or refer to REMOVAL [03/2018 - 08/2019]

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 [08/2016 - 03/2018]  , or refer to  REMOVAL [03/2018 - 08/2019] 

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]  , or refer to  REMOVAL [03/2018 - 08/2019] 

Result: 

NG 

See step  6

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 [08/2016 - 03/2018]  , or refer to  REMOVAL [03/2018 - 08/2019] 

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR