Last Modified: 04-05-2023 6.11:8.1.0 Doc ID: RM1000000018QYR
Model Year Start: 2018 Model: Sienna Prod Date Range: [11/2017 -           ]
Title: NAVIGATION / MULTI INFO DISPLAY: NAVIGATION SYSTEM: B1543; Extension Module Disconnected 2; 2018 - 2020 MY Sienna [11/2017 -        ]

DTC

B1543

Extension Module Disconnected 2

DESCRIPTION

If the radio and display receiver assembly cannot detect the navigation ECU for a certain period of time (90 seconds) after the ignition switch is turned ON 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.

DTC Code

DTC Detection Condition

Trouble Area

B1543

Navigation ECU disconnected

  • Navigation ECU
  • Radio and display receiver assembly
  • No. 1 navigation wire
  • Harness or connector

HINT:

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

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

  • 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 is stored.
    • The radio and display receiver assembly or navigation ECU may not operate normally.

PROCEDURE

1.

CHECK MAP SCREEN

(a) Turn the ignition switch ON and wait for 90 seconds.

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

Result

Proceed to

Map screen is displayed normally

A

Map screen is not displayed normally

B

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

2.

CHECK DTC

(a) Clear the DTCs.

(b) Turn the ignition switch off.

(c) Turn the ignition switch ON 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

3.

CHECK HARNESS AND CONNECTOR (NAVIGATION ECU - BATTERY AND BODY GROUND)

(a) Disconnect the 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:

Tester Connection

Condition

Specified Condition

D199-23 (GND) - Body ground

Always

Below 1 Ω

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

D199-10 (+B) - Body ground

Always

11 to 14 V

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

4.

CHECK NO. 1 NAVIGATION WIRE (RADIO AND DISPLAY RECEIVER ASSEMBLY - NAVIGATION ECU)

(a) Disconnect the V14 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 V12 radio and display receiver assembly connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

V14-4 (US4+) - V12-1 (US4+)

Always

Below 1 Ω

V14-5 (US4-) - V12-2 (US4-)

Always

Below 1 Ω

V14-6 (UGD4) - V12-3 (UGD4)

Always

Below 1 Ω

NG

REPLACE NO. 1 NAVIGATION WIRE

OK

5.

REPLACE NAVIGATION ECU

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

Click here 2018 - 2020 MY Sienna [11/2017 -        ]; NAVIGATION / MULTI INFO DISPLAY: NAVIGATION ECU: REMOVAL

NEXT

6.

CHECK DTC

(a) Clear the DTCs.

(b) Turn the ignition switch off.

(c) Turn the ignition switch ON 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