DTC B1591: No Response from Audio HU; DTC B15D1: Audio HU Disconnected: Procedure

CHECK OPTIONAL COMPONENTS (INCLUDING ASSOCIATED WIRING)

Check for optional components.

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:

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

B → See step 3

A: Go to next step

REMOVE OPTIONAL COMPONENTS (INCLUDING ASSOCIATED WIRING)
1. Remove optional components (including associated wiring).
  NOTE:
  Do not remove optional components or associated wiring without the permission of the customer.
NEXT: Go to next step
CHECK DTC
1. Clear the DTCs. Refer to DTC CHECK / CLEAR .
2. Recheck for DTCs and check if the same DTC is output again.
  OK
  
  No DTCs are output.
NG → See step 4

OK → END

CHECK HARNESS AND CONNECTOR (RADIO RECEIVER ASSEMBLY POWER SOURCE)

Disconnect the radio receiver assembly connector.

Fig 1: Radio Receiver Assembly Connector End View
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

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

Standard Resistance

Tester Connection	Condition	Specified Condition
J106-15 (GND) - Body ground	Always	Below 1 Ω

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

Standard Voltage

Tester Connection	Condition	Specified Condition
J106-14 (B) - J106-15 (GND)	Always	11 to 14 V

TEXT IN ILLUSTRATION

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

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: Go to next step

CHECK HARNESS AND CONNECTOR (MOST COMMUNICATION LINE)

Disconnect the radio receiver assembly connector.
Disconnect the stereo component amplifier assembly connector.
Disconnect the display and navigation module display connector.

Measure the resistance between the display and navigation module display and the radio receiver assembly according to the value(s) in the table below.

Standard Resistance

Tester Connection	Condition	Specified Condition
J101-3 (MO+) - J106-9 (MI+)	Always	Below 1 Ω
J101-7 (MO-) - J106-23 (MI-)	Always	Below 1 Ω
J101-6 (SLDO) - J106-10 (SLDI)	Always	Below 1 Ω
J101-3 (MO+) - Body ground	Always	10 kΩ or higher
J101-7 (MO-) - Body ground	Always	10 kΩ or higher
J101-6 (SLDO) - Body ground	Always	10 kΩ or higher

Measure the resistance between the radio receiver assembly and the stereo component amplifier assembly according to the value(s) in the table below.

Standard Resistance

Tester Connection	Condition	Specified Condition
J106-11 (MO+) - P43-4 (MI+)	Always	Below 1 Ω
J106-25 (MO-) - P43-10 (MI-)	Always	Below 1 Ω
J106-24 (SLDI) - P43-5 (SLDI)	Always	Below 1 Ω
J106-11 (MO+) - Body ground	Always	10 kΩ or higher
J106-25 (MO-) - Body ground	Always	10 kΩ or higher
J106-24 (SLDI) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR

OK: Go to next step

REPLACE RADIO RECEIVER ASSEMBLY
1. Replace the radio receiver assembly. Refer to REMOVAL .
2. Clear the DTCs. Refer to DTC CHECK / CLEAR .
3. Recheck for DTCs and check if the same DTC is output again.
  OK
  
  No DTCs are output.
NG → See step 7

OK → END
REPLACE DISPLAY AND NAVIGATION MODULE DISPLAY. Refer to REMOVAL