Toyota Avalon (XX50): AVC-LAN Circuit. Stereo Component Amplifier Malfunction (B15A3). GPS Antenna Connection Malfunction(short) (B15C0,B15C1)

Toyota Avalon (XX50) 2019-2022 Service & Repair Manual / Audio, Visual, Telematics / Audio / Video / Audio And Visual System(for Gasoline Model) / AVC-LAN Circuit. Stereo Component Amplifier Malfunction (B15A3). GPS Antenna Connection Malfunction(short) (B15C0,B15C1)

AVC-LAN Circuit

DESCRIPTION

Each unit of the audio and visual system connected to the AVC-LAN (communication bus) transmits signals via AVC-LAN communication.

If a short to +B or short to ground occurs in an AVC-LAN communication line, the audio and visual system will not function normally because communication is not possible.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

Depending on the parts that are replaced during vehicle inspection or maintenance, performing initialization, registration or calibration may be needed. Refer to Precaution for Audio and Visual System.
Click here
When replacing the radio and display receiver assembly, always replace it with a new one. If a radio and display receiver assembly which was installed to another vehicle is used, the following may occur:
- A communication malfunction DTC may be stored.
- The radio and display receiver assembly may not operate normally.

HINT:

The radio and display receiver assembly is the master unit.

PROCEDURE

1.	INSPECT RADIO AND DISPLAY RECEIVER ASSEMBLY

(a) Remove the radio and display receiver assembly.

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
G3-5 (TX1+) - G3-6 (TX1-)	Always	60 to 80 Ω

*a	Component without harness connected (Radio and Display Receiver Assembly)

REPLACE RADIO AND DISPLAY RECEIVER ASSEMBLY

2.	CHECK HARNESS AND CONNECTOR (AVC-LAN CIRCUIT)

(a) Disconnect the G3 radio and display receiver assembly connector.

(b) Disconnect the G8 stereo component amplifier assembly connector.

Standard Resistance:

Tester Connection	Condition	Specified Condition
G8-8 (TX+) - G3-5 (TX1+)	Always	Below 1 Ω
G8-7 (TX-) - G3-6 (TX1-)	Always	Below 1 Ω
G8-8 (TX+) or G3-5 (TX1+) - Body ground	Always	10 kΩ or higher
G8-7 (TX-) or G3-6 (TX1-) - Body ground	Always	10 kΩ or higher

REPAIR OR REPLACE HARNESS OR CONNECTOR

3.	INSPECT MALFUNCTIONING PARTS

(a) Disconnect and reconnect each slave unit one by one until the master unit returns to normal.

HINT:

Check all slave units.
If disconnecting a slave unit causes the master unit to return to normal, the slave unit is defective and should be replaced.

OK:

Master unit returns to normal.

REPLACE MALFUNCTIONING PARTS

REPLACE RADIO AND DISPLAY RECEIVER ASSEMBLY

Stereo Component Amplifier Malfunction (B15A3)

DESCRIPTION

This DTC is stored when a malfunction occurs in the stereo component amplifier assembly.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area
B15A3	Stereo Component Amplifier Malfunction	When any of the following conditions is met: Internal power supply malfunction DSP error EEPROM error	Stereo component amplifier assembly

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

B15A3

Stereo Component Amplifier Malfunction

When any of the following conditions is met:

Internal power supply malfunction
DSP error
EEPROM error

Stereo component amplifier assembly

PROCEDURE

CHECK DTC

(a) Clear the DTCs.

Body Electrical > Navigation System > Clear DTCs

(b) Recheck for DTCs and check that no DTCs are output.

Body Electrical > Navigation System > Trouble Codes

OK:

No DTCs are output.

USE SIMULATION METHOD TO CHECK

REPLACE STEREO COMPONENT AMPLIFIER ASSEMBLY

GPS Antenna Connection Malfunction(short) (B15C0,B15C1)

DESCRIPTION

These DTCs are stored when a malfunction occurs in the navigation antenna assembly.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area
B15C0	GPS Antenna Connection Malfunction(short)	Navigation antenna malfunction	Navigation antenna assembly No. 4 antenna cord sub-assembly No. 5 antenna cord sub-assembly Radio and display receiver assembly
B15C1	GPS Antenna Connection Malfunction(break)	Navigation antenna power source malfunction	Navigation antenna assembly No. 4 antenna cord sub-assembly No. 5 antenna cord sub-assembly Radio and display receiver assembly

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

Depending on the parts that are replaced during vehicle inspection or maintenance, performing initialization, registration or calibration may be needed. Refer to Precaution for Audio and Visual System.
Click here
When replacing the radio and display receiver assembly, always replace it with a new one. If a radio and display receiver assembly which was installed to another vehicle is used, the following may occur:
- A communication malfunction DTC may be stored.
- The radio and display receiver assembly may not operate normally.
Check that the No. 4 antenna cord sub-assembly and No. 5 antenna cord sub-assembly is properly installed and does not have any sharp bends, pinching or loose connections before performing following procedure.
Click here

PROCEDURE

CHECK DTC

(a) Clear the DTCs.

Body Electrical > Navigation System > Clear DTCs

(b) Recheck for DTCs and check that no DTCs are output.

Body Electrical > Navigation System > Trouble Codes

OK:

No DTCs are output.

USE SIMULATION METHOD TO CHECK

2.	INSPECT NO. 5 ANTENNA CORD SUB-ASSEMBLY

(a) Remove the No. 5 antenna cord sub-assembly.

Click here

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
C-1 - D-1	Always	Below 1 Ω
C-1a - D-1a	Always	Below 1 Ω
C-1 or D-1 - Body ground	Always	10 kΩ or higher

*a	Component without harness connected (No. 5 Antenna Cord Sub-assembly)

REPLACE NO. 5 ANTENNA CORD SUB-ASSEMBLY

3.	INSPECT NO. 4 ANTENNA CORD SUB-ASSEMBLY

(a) Remove the No. 4 antenna cord sub-assembly.

Click here

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
A-3 - B-1	Always	Below 1 Ω
A-3a - B-1a	Always	Below 1 Ω
A-3 or B-1 - Body ground	Always	10 kΩ or higher

*a	Component without harness connected (No. 4 Antenna Cord Sub-assembly)

REPLACE NO. 4 ANTENNA CORD SUB-ASSEMBLY

4.	INSPECT NAVIGATION ANTENNA ASSEMBLY

(a) Remove the navigation antenna assembly.

Click here

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

Standard Resistance:

Tester Connection	Condition	Specified Condition
3 - 3a	Always	50 to 500 Ω

*a	Component without harness connected (Navigation Antenna Assembly)

REPLACE RADIO AND DISPLAY RECEIVER ASSEMBLY

REPLACE NAVIGATION ANTENNA ASSEMBLY

Audio And Visual System(for Gasoline Model)

Speaker Output Short (B15C3)

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