Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual: Power Source Circuit

Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual / Vehicle Interior / Theft Deterrent / Keyless Entry / Theft Deterrent System / 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 2C 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

2C-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

2C-1 - MB-31 (BECU)

Always

Below 1 Ω
OK

REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

NG

REPLACE INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY

    Theft Warning Siren Circuit
    DESCRIPTION The theft warning siren assembly sounds if either of the following conditions is met: The theft deterrent system is in the alarm sounding state. The theft warning siren assembly is in ...

    Other materials:

    Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual > Dynamic Torque Control Awd System: Linear Solenoid Power Supply System Malfunction (C120C)
    DESCRIPTION This DTC is output by the 4WD ECU assembly if a malfunction occurs in the linear solenoid power supply system. DTC No. Detection Item DTC Detection Condition Trouble Area C120C Linear Solenoid Power Supply System Malfunction When the 4WD relay is operating, the 4WD re ...

    Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual > Airbag System: Operation Check
    OPERATION CHECK PRECAUTION FOR OPERATION CHECK CAUTION: Use the correct procedure to replace the airbag parts. CHECK SRS WARNING LIGHT (a) Primary check (1) Turn the engine switch on (IG) and check that the SRS warning light turns on. (2) Turn the engine switch off. Wait for at least 2 seconds, an ...

    Lexus RX (RX 350L, RX450h) 2016-{YEAR} Owners Manual

    Lexus RX (RX 350L, RX450h) 2016-{YEAR} Repair Manual

    © 2025 Copyright www.lexusrx.net
    0.0141