Toyota Avalon (XX50) 2019-2022 Service & Repair Manual: Power Source Circuit

DESCRIPTION

Based on changes in the power source voltage, the main body ECU (multiplex network body ECU) can detect if the battery has been disconnected and reconnected.

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

  • Before replacing the main body ECU (multiplex network body ECU), refer to Registration.

    Click here

  • Inspect the fuses for circuits related to this system before performing the following procedure.

PROCEDURE

1.

CHECK HARNESS AND CONNECTOR (POWER SUPPLY)

(a) Disconnect the 4F instrument panel junction block assembly connector.

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

Standard Voltage:

Tester Connection

Condition

Specified Condition

4F-1 - Body ground

Always

8.5 V or higher

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

2.

INSPECT INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

(a) Remove the main body ECU (multiplex network body ECU).

Click here

*a

Component without harness connected

(Instrument Panel Junction Block Assembly)

-

-

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

4F-1 - MB-31 (BECU)

Always

Below 1 Ω

OK

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

NG

REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

    Parts Location

    Precaution

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