Toyota Avalon (XX50) 2019-2022 Service & Repair Manual: Extension Module Disconnected 2 (B1543)

DESCRIPTION

If the radio and display receiver assembly cannot detect the navigation ECU for a certain period of time (90 seconds) after the engine switch is turned on (ACC) and the radio and display receiver assembly confirms that the information is missing by checking past navigation ECU recognition information (registered information), this DTC will be stored.

HINT:

The Navigation system uses USB communication between devices. If an open, short, short to +B or short to ground occurs in the USB circuit, communication is interrupted and the Navigation system will not operate normally.

HINT:

This DTC may be stored due to environmental reasons such as electrical noise or interference.

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 Navigation System.

  Click here

• Inspect the fuses for circuits related to this system before performing the following procedure.
• When replacing the radio and display receiver assembly or navigation ECU, always replace it with a new one. If a radio and display receiver assembly or navigation ECU 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 or navigation ECU may not operate normally.

PROCEDURE

(a) Turn the engine switch on (ACC) and wait for 90 seconds.

(b) Press the "MAP" switch and check that the map screen is displayed normally.

HINT:

• This DTC may be stored due to environmental reasons such as electrical noise or interference.
• Clear past DTCs when the map screen is displayed normally. (Codes stored due to past environmental factors)

A

USE SIMULATION METHOD TO CHECK

B

(a) Clear the DTCs.

(b) Turn the engine switch off.

(c) Turn the engine switch on (IG) and wait for 90 seconds.

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

OK:

No DTCs are output.

OK

USE SIMULATION METHOD TO CHECK

NG

(a) Disconnect the G13 navigation ECU connector.

*a Front view of wire harness connector (to Navigation ECU)

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

Standard Resistance:

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

Standard Voltage:

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

(a) Disconnect the G109 navigation ECU connector.

*a Front view of wire harness connector (to Radio and Display Receiver Assembly) *b Front view of wire harness connector (to Navigation ECU)

(b) Disconnect the G111 radio and display receiver assembly connector.

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

Standard Resistance:

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

(a) Replace the navigation ECU with a new one.

Click here

NEXT

(a) Clear the DTCs.

(b) Turn the engine switch off.

(c) Turn the engine switch on (IG) and wait for 90 seconds.

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

OK:

No DTCs are output.

OK

END (NAVIGATION ECU IS DEFECTIVE)

NG

REPLACE RADIO AND DISPLAY RECEIVER ASSEMBLY