Lexus RX (RX 350L, RX450h) 2016-2026 Repair Manual: Terminals Of Ecu

Lexus RX (RX 350L, RX450h) 2016-2026 Repair Manual / Vehicle Interior / Theft Deterrent / Keyless Entry / Theft Deterrent System / Terminals Of Ecu

TERMINALS OF ECU

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

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

Click here

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

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

HINT:

Measure the values on the wire harness side with the connector disconnected.

Terminal No. (Symbol)

Wiring Color

Terminal Description

Condition

Specified Condition

MB-31 (BECU) - Body ground

-

Battery power supply

Always

11 to 14 V

MB-32 (IG) - Body ground

-

Ignition power supply (IG signal)

Engine switch off

Below 1 V

Engine switch on (IG)

11 to 14 V

MB-30 (ACC) - Body ground

-

Ignition power supply (ACC signal)

Engine switch off

Below 1 V

Engine switch on (ACC)

11 to 14 V

MB-11 (GND1) - Body ground

-

Ground

Always

Below 1 Ω

J8-6 (FLCY) - Body ground

P - Body ground

Front door courtesy light switch assembly (for LH) input

Front door LH closed

10 kΩ or higher

Front door LH open

Below 1 Ω

J8-27 (FRCY) - Body ground

R - Body ground

Front door courtesy light switch assembly (for RH) input

Front door RH closed

10 kΩ or higher

Front door RH open

Below 1 Ω

MB-13 (LCTY) - Body ground

-

Rear door courtesy light switch assembly (for LH) input

Rear door LH closed

10 kΩ or higher

Rear door LH open

Below 1 Ω

MB-2 (RCTY) - Body ground

-

Rear door courtesy light switch assembly (for RH) input

Rear door RH closed

10 kΩ or higher

Rear door RH open

Below 1 Ω

J8-11 (HCTY) - Body ground

R - Body ground

Engine hood courtesy switch input

Engine hood open

10 kΩ or higher

Engine hood closed

Below 1 Ω

MB-14 (TRLY) - Body ground

-

Taillight relay drive output

Always

11 to 14 V

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

Click here

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

Terminal No. (Symbol)

Wiring Color

Terminal Description

Condition

Specified Condition

2B-13 (LSFL) - Body ground

B - Body ground

Front door LH unlock detection switch input

Front door LH unlocked

Below 1 V

Front door LH locked

Pulse generation

2B-12 (LSFR) - Body ground

P - Body ground

Front door RH unlock detection switch input

Front door RH unlocked

Below 1 V

Front door RH locked

Pulse generation

J8-29 (L2) - Body ground

P - Body ground

Driver door key-linked lock input

Driver door key cylinder turned to lock position

Below 1 V

Driver door key cylinder off

Pulse generation

J8-2 (UL3) - Body ground

V - Body ground

Driver door key-linked unlock input

Driver door key cylinder turned to unlock position

Below 1 V

Driver door key cylinder off

Pulse generation

2B-14 (LSWL) - Body ground

V - Body ground

Rear door LH unlock detection switch input

Rear door LH unlocked

Below 1 V

Rear door LH locked

Pulse generation

J9-2 (LSWR) - Body ground

L - Body ground

Rear door RH unlock detection switch input

Rear door RH unlocked

Below 1 V

Rear door RH locked

Pulse generation

2C-26 (SH) - Body ground*1

L - Body ground

Security horn assembly drive

Security horn assembly sounding

(Theft deterrent system in alarm sounding state)

Pulse generation

(Below 1 V ← → 11 to 14 V)

J9-18 (SSCL) - Body ground*2

W - Body ground

Theft warning siren assembly drive

Theft warning siren assembly sounding

(Theft deterrent system in alarm sounding state)

Pulse generation

(Below 1 V ← → 11 to 14 V)

2C-27 (HORN) - Body ground

G - Body ground

Vehicle horns drive

Vehicle horns sounding

(Theft deterrent system in alarm sounding state)

Pulse generation

(Below 1 V ← → 11 to 14 V)

2C-31 (HRLY) - Body ground

V - Body ground*3

B - Body ground*4

Headlight relay drive output

Low beams blinking

(Theft deterrent system in alarm sounding state)

Pulse generation

(Below 1 V ← → 11 to 14 V)

2B-29 (ILE) - Body ground

GR - Body ground

Interior lights drive output

Interior lights illuminated

(Theft deterrent system in alarm sounding state)

Below 1 V
  • *1: w/ Security Horn Assembly
  • *2: w/o Security Horn Assembly
  • *3: w/ Automatic Headlight Beam Level Control System
  • *4: w/o Automatic Headlight Beam Level Control System
    Problem Symptoms Table
    PROBLEM SYMPTOMS TABLE NOTICE: Before replacing the main body ECU (multiplex network body ECU), refer to Registration. Click here HINT: Troubleshooting of the theft deterrent system is based on ...

    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. Th ...

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

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

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