Lexus RX (RX 350L, RX450h) 2016-2026 Repair Manual: Power Source Circuit

Lexus RX (RX 350L, RX450h) 2016-2026 Repair Manual / Vehicle Interior / Seat / Rear Power Seat Control System(for Second Row) / Power Source Circuit

DESCRIPTION

Power is supplied to the fold seat control ECU through the ECU-DCC NO. 2, P/SEAT R/R*1, P/SEAT R/L*2 and ECU-IG1 NO. 4 fuses.

  • *1: for Rear Right Seat
  • *2: for Rear Left Seat

WIRING DIAGRAM

CAUTION / NOTICE / HINT

HINT:

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

PROCEDURE

1.

CHECK HARNESS AND CONNECTOR (FOLD SEAT CONTROL ECU - BATTERY AND BODY GROUND)

*A

for Rear RH Seat

*B

for Rear LH Seat

*a

Front view of wire harness connector (to Fold Seat Control ECU)

(a) Disconnect the x3*1 or y3*2 and x4*1 or y4*2 fold seat control ECU (rear right seat) connectors.

  • *1: for Rear RH Seat
  • *2: for Rear LH Seat

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

Standard Voltage:

for Rear RH Seat

Tester Connection

Condition

Specified Condition

x4-1 (IND1) - Body ground

Always

11 to 14 V

x4-2 (+B) - Body ground

Always

11 to 14 V

x3-1 (ECUB) - Body ground

Always

11 to 14 V

x3-3 (IG) - Body ground

Engine switch off → on (IG)

Below 1 V → 11 to 14 V
for Rear LH Seat

Tester Connection

Condition

Specified Condition

y4-1 (IND1) - Body ground

Always

11 to 14 V

y4-2 (+B) - Body ground

Always

11 to 14 V

y3-1 (ECUB) - Body ground

Always

11 to 14 V

y3-3 (IG) - Body ground

Engine switch off → on (IG)

Below 1 V → 11 to 14 V

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

Standard Resistance:

for Rear RH Seat

Tester Connection

Condition

Specified Condition

x4-10 (GND) - Body ground

Always

Below 1 Ω

x4-9 (GND2) - Body ground

Always

Below 1 Ω

x3-40 (IND2) - Body ground

Always

Below 1 Ω
for Rear LH Seat

Tester Connection

Condition

Specified Condition

y4-10 (GND) - Body ground

Always

Below 1 Ω

y4-9 (GND2) - Body ground

Always

Below 1 Ω

y3-40 (IND2) - Body ground

Always

Below 1 Ω
OK

GO TO PROBLEM SYMPTOMS TABLE

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
    Fold Seat Switch Circuit
    DESCRIPTION When the fold seat switch assembly is operated, a switch operation signal is sent to the fold seat control ECU. According to the signal received, the fold seat control ECU operates the fol ...

    Folding Motor Circuit
    DESCRIPTION HINT: The rear power seat switch is a collective term for the rear power seat switch RH and the rear power seat switch LH. The rear seatback frame sub-assembly is a collective term fo ...

    Other materials:

    Lexus RX (RX 350L, RX450h) 2016-2026 Repair Manual > Power Mirror Control System (w/ Memory): Diagnostic Trouble Code Chart
    DIAGNOSTIC TROUBLE CODE CHART Power Mirror Control System (w/ Memory) DTC No. Detection Item Link U0142 Lost Communication with Main Body ECU ...

    Lexus RX (RX 350L, RX450h) 2016-2026 Repair Manual > Power Back Door System (w/ Outside Door Control Switch): System Diagram
    SYSTEM DIAGRAM Communication Table Transmitting ECU Receiving ECU Signal Communication Method Main body ECU (multiplex network body ECU) Multiplex network door ECU Power back door ON/OFF signal Combination switch assembly signal Power back door switch (integration control ...

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

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

    © 2026 Copyright www.lexusrx.net
    0.0118