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 > Audio And Visual System (for 12.3 Inch Display): Microphone Circuit
    DESCRIPTION The radio receiver assembly and telephone microphone assembly are connected to each other using the microphone connection detection signal lines. Using this circuit, the radio receiver assembly sends power to the telephone microphone assembly, and the telephone microphone assembly s ...

    Lexus RX (RX 350L, RX450h) 2016-2026 Repair Manual > Occupant Classification System: Occupant Classification ECU Malfunction (B1795)
    DESCRIPTION DTC B1795 is stored when a malfunction is detected in the occupant detection ECU. DTC No. Detection Item DTC Detection Condition Trouble Area B1795 Occupant Classification ECU Malfunction Occupant detection ECU malfunction Occupant detection ECU CAUTION / NOTICE / H ...

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

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

    © 2026 Copyright www.lexusrx.net
    0.0099