Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual: Emergency Call Switch Illumination Circuit

Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual / Audio & Visual & Telematics / Cellular Communication / Safety Connect System / Emergency Call Switch Illumination Circuit

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

  • Depending on the parts that are replaced during vehicle inspection or maintenance, performing initialization, registration or calibration may be needed. Refer to Precaution for Safety Connect System.

    Click here

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

PROCEDURE

1.

CHECK HARNESS AND CONNECTOR (MAP LIGHT ASSEMBLY (MANUAL (SOS) SWITCH) POWER SOURCE)

(a) Disconnect the J157 DCM (telematics transceiver) connector.

(b) Disconnect the U12 map light assembly (manual (SOS) switch) connector.

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

Standard Voltage:

Tester Connection

Switch Condition

Specified Condition

U12-5 (RRID) - Body Ground

Engine switch on (IG)

11 to 14 V

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

Standard Resistance:

Tester Connection

Condition

Specified Condition

J157-3 (SIG-) - U12-9 (GND3)

Always

Below 1 Ω

J157-3 (SIG-) or U12-9 (GND3) - Body ground

Always

10 kΩ or higher
NG

REPAIR OR REPLACE HARNESS OR CONNECTOR
OK

2.

INSPECT MAP LIGHT ASSEMBLY (MANUAL (SOS) SWITCH)

(a) Remove the map light assembly (manual (SOS) switch).

Click here

*a

Component without harness connected

(Map Light Assembly (Manual (SOS) Switch))

(b) Apply battery voltage to the connector and check that the roof console box assembly comes on.

OK:

Measurement Condition

Condition

Specified Condition

Battery positive (+) → U12-5 (RRID)

Battery negative (-) → U12-9 (GND3)

Always

Manual (SOS) switch illumination cones on
NG

REPLACE MAP LIGHT ASSEMBLY (MANUAL (SOS) SWITCH)

OK

3.

REPLACE DCM (TELEMATICS TRANSCEIVER)

(a) Replace the DCM (telematics transceiver) with a new one.

Click here

NOTICE:

  • The engine switch must be off.
  • Do not exchange the DCM (telematics transceiver) with one from another vehicle.
NEXT

PERFORM DCM ACTIVATION

    Unable To Connect To Call Center
    DESCRIPTION This may occur when the intensity of telephone radio frequency was very weak, or the safety connect system has a malfunction and a DTC is set. PROCEDURE 1. CHECK COMMUNICATION SERVIC ...

    Telephone And Gps Antenna (for Front Side)
    ...

    Other materials:

    Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual > Heated Steering Wheel System: 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) 2016-2025 Repair Manual > Dynamic Torque Control Awd System: Diagnosis System
    DIAGNOSIS SYSTEM DESCRIPTION Dynamic torque control AWD system data and Diagnostic Trouble Codes (DTCs) can be read through the Data Link Connector 3 (DLC3) of the vehicle. When the system seems to be malfunctioning, use the Techstream to check for malfunctions and perform repairs. CHECK DATA LINK C ...

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

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

    © 2025 Copyright www.lexusrx.net
    0.0124