DTC    B1591    No Response from Audio HU

DTC    B15D1    Audio HU Disconnected

for Preparation Click here


DESCRIPTION

The navigation computer sub-assembly and radio receiver assembly are connected by the MOST communication line.
When a MOST communication error occurs between the navigation computer sub-assembly and radio receiver assembly, these DTCs will be stored.

DTC No.
DTC Detection Condition
Trouble Area
B1591
No response to the diagnostic memory request from the master unit.
  1. Radio receiver assembly power source circuit
  2. MOST circuit between navigation computer sub-assembly and radio receiver assembly
  3. MOST circuit between radio receiver assembly and stereo component amplifier assembly
  4. Radio receiver assembly
  5. Navigation computer sub-assembly
B15D1
A device that is listed in the MOST network connected device record of the master unit is missing.

HINT:
For the MOST network, the navigation computer sub-assembly is the master unit.


WIRING DIAGRAM


E223963E02


INSPECTION PROCEDURE

NOTICE:
Inspect the fuse for circuits related to this system before performing the following inspection procedure.

1.CHECK OPTIONAL COMPONENTS (INCLUDING ASSOCIATED WIRING)

  1. Check for optional components.

    1. Check that optional components (including associated wiring) which generate radio waves are not installed.

      Result:
      Result
      		Proceed to
      Optional components (including associated wiring) are installed.
      		A
      Optional components (including associated wiring) are not installed.
      		B

      HINT:
      1. Electrical noise from radio waves generated by optional components or the wiring for those components may affect MOST communication.
      2. This DTC may be stored when a MOST communication error occurs due to electrical noise.



B
Go to step 3
A


2.REMOVE OPTIONAL COMPONENTS (INCLUDING ASSOCIATED WIRING)

  1. Remove optional components (including associated wiring).

    NOTICE:
    Do not remove optional components or associated wiring without the permission of the customer.


NEXT


3.CHECK DTC

  1. Clear the DTCs (Click here).

  1. Recheck for DTCs and check if the same DTCs are output again.

    OK:
    No DTCs are output.



NG
Go to step 4
OK

END 

4.CHECK HARNESS AND CONNECTOR (RADIO RECEIVER ASSEMBLY POWER SOURCE)

  1. Disconnect the H50 radio receiver assembly connector.

  1. Measure the resistance according to the value(s) in the table below.

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    H50-15 (GND) - Body ground
    		Always
    		Below 1 Ω

  1. Measure the voltage according to the value(s) in the table below.

    Standard Voltage:
    Tester Connection
    		Condition
    		Specified Condition
    H50-14 (B) - H50-15 (GND)
    		Power switch off
    		11 to 14 V



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


5.CHECK HARNESS AND CONNECTOR

  1. Disconnect the H50 radio receiver assembly connector.

  1. Disconnect the H62 navigation computer sub-assembly connector.

  1. Measure the resistance according to the value(s) in the table below.

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    H50-9 (MI+) - H62-3 (MO+)
    		Always
    		Below 1 Ω
    H50-23 (MI-) - H62-7 (MO-)
    		Always
    		Below 1 Ω
    H50-10 (SLDI) - H62-6 (SLDO)
    		Always
    		Below 1 Ω
    H50-9 (MI+) - Body ground
    		Always
    		10 kΩ or higher
    H50-23 (MI-) - Body ground
    		Always
    		10 kΩ or higher
    H50-10 (SLDI) - Body ground
    		Always
    		10 kΩ or higher



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


6.CHECK HARNESS AND CONNECTOR

  1. Disconnect the H50 radio receiver assembly connector.

  1. Disconnect the H56 stereo component amplifier assembly connector.

  1. Measure the resistance according to the value(s) in the table below.

    Standard Resistance:
    Tester Connection
    		Condition
    		Specified Condition
    H50-11 (MO+) - H56-4 (MI+)
    		Always
    		Below 1 Ω
    H50-25 (MO-) - H56-10 (MI-)
    		Always
    		Below 1 Ω
    H50-24 (SLDI) - H56-5 (SLDI)
    		Always
    		Below 1 Ω
    H50-11 (MO+) - Body ground
    		Always
    		10 kΩ or higher
    H50-25 (MO-) - Body ground
    		Always
    		10 kΩ or higher
    H50-24 (SLDI) - Body ground
    		Always
    		10 kΩ or higher



NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
OK


7.REPLACE RADIO RECEIVER ASSEMBLY

  1. Replace the radio receiver assembly (Click here).

  1. Clear the DTCs (Click here).

  1. Recheck for DTCs and check if the same DTCs are output again.

    OK:
    No DTCs are output.



NG
REPLACE NAVIGATION COMPUTER SUB-ASSEMBLY (Click here)
OK

END