Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual: Back Door Courtesy Switch Circuit

DESCRIPTION

The multiplex network door ECU receives the courtesy light switch signal from the back door lock assembly and transmits it to the main body ECU (multiplex network body ECU) via CAN communication.

WIRING DIAGRAM

PROCEDURE

1.

READ VALUE USING TECHSTREAM

(a) Connect the Techstream to the DLC3.

(b) Turn the engine switch on (IG).

(c) Turn the Techstream on.

(d) Enter the following menus: Body Electrical / Back Door / Data List.

(e) Read the Data List according to the display on the Techstream.

Body Electrical > Back Door > Data List

Tester Display

Measurement Item

Range

Normal Condition

Diagnostic Note

Courtesy SW

Latch courtesy switch signal

ON or OFF

ON: Back door open

OFF: Back door closed

-

Body Electrical > Back Door > Data List

Tester Display

Courtesy SW

OK:

Normal conditions listed above are displayed.

OK

PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE

NG

2.

INSPECT BACK DOOR LOCK ASSEMBLY

(a) Remove the back door lock assembly.

Click here

(b) Inspect the back door courtesy switch built in the back door lock assembly.

Click here

OK:

Back door lock assembly is normal.

NG

REPLACE BACK DOOR LOCK ASSEMBLY

OK

3.

CHECK HARNESS AND CONNECTOR (BACK DOOR LOCK ASSEMBLY - MULTIPLEX NETWORK DOOR ECU AND BODY GROUND)

(a) Disconnect the Z16 multiplex network door ECU connector.

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

Z7-8 - Z16-11 (FUL)

Always

Below 1 Ω

Z7-8 or Z16-11 (FUL) - Body ground

Always

10 kΩ or higher

Z7-7 - Body ground

Always

Below 1 Ω

OK

REPLACE MULTIPLEX NETWORK DOOR ECU

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

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