Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual: Terminals Of Ecu

Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual / Vehicle Interior / Door Lock / Wireless Door Lock Control System / Terminals Of Ecu

TERMINALS OF ECU

CHECK INSTRUMENT PANEL JUNCTION BLOCK ASSEMBLY AND MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU)

(a) Remove the main body ECU (multiplex network body ECU) from the instrument panel junction block assembly.

(b) Reconnect the instrument panel junction block assembly connector.

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

Tester Connection

Wiring Color

Terminal Description

Condition

Specified Condition

MB-11 (GND1) - Body ground

-

Ground

Always

Below 1 Ω

MB-30 (ACC) - Body ground

-

ACC power supply

Engine switch on (ACC)

11 to 14 V

MB-30 (ACC) - Body ground

-

ACC power supply

Engine switch off

Below 1 V

MB-31 (BECU) - Body ground

-

Battery power supply

Always

11 to 14 V

MB-32 (IG) - Body ground

-

IG power supply

Engine switch on (IG)

11 to 14 V

MB-32 (IG) - Body ground

-

IG power supply

Engine switch off

Below 1 V

(d) Install the main body ECU (multiplex network body ECU) to the instrument panel junction block assembly.

(e) Measure the voltage and check for pulses according to the value(s) in the table below.

Tester Connection

Wiring Color

Terminal Description

Condition

Specified Condition

J9-2 (LSWR) - Body ground

L - Body ground

Rear door RH unlock detection switch input

Rear door RH unlocked

Below 1 V

J9-2 (LSWR) - Body ground

L - Body ground

Rear door RH unlock detection switch input

Rear door RH locked

Pulse generation

J8-2 (UL3) - Body ground

V - Body ground

Driver door key-linked unlock input

Driver door key cylinder turned to neutral position → on (unlock)

Pulse generation → Below 1 V

J8-6 (FLCY) - Body ground

P - Body ground

Front door courtesy light switch (for LH) input

Front door LH open

Below 1 V

J8-6 (FLCY) - Body ground

P - Body ground

Front door courtesy light switch (for LH) input

Front door LH closed

Pulse generation

J8-27 (FRCY) - Body ground

R - Body ground

Front door courtesy light switch (for RH) input

Front door RH open

Below 1 V

J8-27 (FRCY) - Body ground

R - Body ground

Front door courtesy light switch (for RH) input

Front door RH closed

Pulse generation

J8-29 (L2) - Body ground

P - Body ground

Driver door key-linked lock input

Driver door key cylinder turned to neutral position → on (lock)

Pulse generation → Below 1 V

2D-8 (ACT-) - Body ground

W - Body ground

Door lock motor unlock drive output

Door control switch or driver door key cylinder off → on (unlock)

Below 1 V → 11 to 14 V → Below 1 V

2D-6 (ACT+) - Body ground

P - Body ground

Door lock motor lock drive output

Door control switch or driver door key cylinder off → on (lock)

Below 1 V → 11 to 14 V → Below 1 V

2D-24 (LCTY) - Body ground

W - Body ground

Rear door courtesy light switch (for LH) input

Rear door LH open

Below 1 V

2D-24 (LCTY) - Body ground

W - Body ground

Rear door courtesy light switch (for LH) input

Rear door LH closed

Pulse generation

2B-14 (LSWL) - Body ground

V - Body ground

Rear door LH unlock detection switch input

Rear door LH unlocked

Below 1 V

2B-14 (LSWL) - Body ground

V - Body ground

Rear door LH unlock detection switch input

Rear door LH locked

Pulse generation

2C-29 (BZR) - Body ground

P - Body ground

Wireless door lock buzzer output

Engine switch off, all doors closed, electrical key transmitter sub-assembly no inside vehicle and lock or unlock switch of electrical key transmitter sub-assembly not pressed → pressed (wireless door lock buzzer answer-back)

Below 1 V → Pulse generation

2B-1 (ACT-) - Body ground

B - Body ground

Door lock motor unlock drive output

Door control switch or driver door key cylinder off → on (unlock)

Below 1 V → 11 to 14 V → Below 1 V

2D-9 (ACT-) - Body ground

B - Body ground

Door lock motor unlock drive output

Door control switch or driver door key cylinder off → on (unlock)

Below 1 V → 11 to 14 V → Below 1 V

2B-4 (ACTD) - Body ground

B - Body ground

Door lock motor unlock drive output

Door control switch or driver door key cylinder off → on (unlock)

Below 1 V → 11 to 14 V → Below 1 V

2D-18 (ACT+) - Body ground

B - Body ground

Door lock motor lock drive output

Door control switch or driver door key cylinder off → on (lock)

Below 1 V → 11 to 14 V → Below 1 V

2B-2 (ACT+) - Body ground

R - Body ground

Door lock motor lock drive output

Door control switch or driver door key cylinder off → on (lock)

Below 1 V → 11 to 14 V → Below 1 V

2A-31 (RCTY) - Body ground

R - Body ground

Rear door courtesy light switch (for RH) input

Rear door RH open

Below 1 V

2A-31 (RCTY) - Body ground

R - Body ground

Rear door courtesy light switch (for RH) input

Rear door RH closed

Pulse generation

2B-12 (LSFR) - Body ground

P - Body ground

Front door RH unlock detection switch input

Front door RH unlocked

Below 1 V

2B-12 (LSFR) - Body ground

P - Body ground

Front door RH unlock detection switch input

Front door RH locked

Pulse generation

2B-13 (LSFL) - Body ground

B - Body ground

Front door LH unlock detection switch input

Front door LH unlocked

Below 1 V

2B-13 (LSFL) - Body ground

B - Body ground

Front door LH unlock detection switch input

Front door LH locked

Pulse generation

CHECK CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

(a) Disconnect the J41 certification ECU (smart key ECU assembly) connector.

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

Tester Connection

Wiring Color

Terminal Description

Condition

Specified Condition

J41-4 (+B) - Body ground

V - Body ground

Battery power supply

Always

11 to 14 V

J41-18 (E) - Body ground

W-B - Body ground

Ground

Always

Below 1 Ω

(c) Reconnect the J41 certification ECU (smart key ECU assembly) connector.

(d) Measure the voltage and check for pulses according to the value(s) in the table below.

Tester Connection

Wiring Color

Terminal Description

Condition

Specified Condition

R1-18 (RCO) - J41-18 (E)

LG - W-B

Output to electrical key and tire pressure monitoring system receiver assembly

(Power supply for electrical key and tire pressure monitoring system receiver assembly. Certification ECU (smart key ECU assembly) outputs 5 V when receiver starts operating.)
Proceed:
  1. The engine switch off
  2. Bring electrical key transmitter sub-assembly outside detection area but within wireless function operational area
  3. Press lock or unlock switch of electrical key transmitter sub-assembly

Below 1 V → 4.5 to 5.5 V

R1-20 (CSEL) - J41-18 (E)

SB - W-B

Communication channel switching circuit
Proceed:
  1. The engine switch off
  2. Close all doors

No pulse generation → Pulse generation

R1-19 (RDAM) - J41-18 (E)

W - W-B

Electrical key and tire pressure monitoring system receiver assembly communication circuit
Proceed:
  1. The engine switch off
  2. All doors locked
  3. Bring electrical key transmitter sub-assembly outside detection area but within wireless function operational area
  4. Press lock or unlock switch of electrical key transmitter sub-assembly

11 to 14 pulse generation at regular intervals → Pulse generation
    Problem Symptoms Table
    PROBLEM SYMPTOMS TABLE HINT: Use the table below to help determine the cause of problem symptoms. If multiple suspected areas are listed, the potential causes of the symptoms are listed in order of ...

    Diagnosis System
    DIAGNOSIS SYSTEM DESCRIPTION The main body ECU (multiplex network body ECU) stores DTCs when malfunctions occur. The diagnostic system allows for reading of the DTCs from the DLC3. Use the Techstream ...

    Other materials:

    Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual > Power Steering System: Data List / Active Test
    DATA LIST / ACTIVE TEST DATA LIST HINT: Using the Techstream to read the Data List allows the values or states of switches, sensors, actuators and other items to be read without removing any parts. This non-intrusive inspection can be very useful because intermittent conditions or signals may be dis ...

    Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual > Front Power Seat Control System (w/ Memory): Precaution
    PRECAUTION PRECAUTION FOR DISCONNECTING CABLE FROM NEGATIVE BATTERY TERMINAL NOTICE: When disconnecting the cable from the negative (-) battery terminal, initialize the following systems after the cable is reconnected. System Name See Procedure Lane Control System Pre-collision Sys ...

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

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

    © 2025 Copyright www.lexusrx.net
    0.014