Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual: Diagnosis System

DIAGNOSIS SYSTEM

DESCRIPTION

(a) Blind spot monitor data and Diagnostic Trouble Codes (DTCs) can be read from the Data Link Connector 3 (DLC3) of the vehicle. When the system seems to be malfunctioning, use the Techstream to check for malfunctions and to perform repairs.

CHECK DLC3

(a) Check the DLC3.

Click here

DIAGNOSIS FUNCTION

(a) The blind spot monitor system displays an error message on the multi-information display to inform the driver that the system is unavailable either temporarily or due to a malfunction.

(b) If the RCTA function is not operating correctly, the blind spot monitor system displays the RCTA icon on the multi-display assembly*1 or accessory meter assembly*2 to inform the driver of the malfunction

Malfunctioning Item	Detection Condition	Malfunction Indication	Suspected Area
System Malfunction Indication	Blind spot monitor sensor LH is malfunctioning Blind spot monitor sensor RH is malfunctioning Blind spot monitor sensor LH communication abnormal	○	Check for DTCs

(1) Malfunction Indication

*A	for 12.3 Inch Display	*B	for 8 Inch Display (w/ Panoramic View Monitor System)
*a	System Malfunction Indication	*b	Communication Malfunction Indication
*c	RCTA Icon	*d	When panoramic view screen not displayed
*e	When panoramic view screen displayed	-	-

ABNORMALITY HISTORY

HINT:

The abnormality history for a blind spot monitor sensor can be displayed or cleared.

(a) Check abnormality history

(1) Connect the Techstream to the DLC3.

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

(3) Turn the Techstream on.

(4) Turn the blind spot monitor system on.

(5) Enter the following menus: Body Electrical / Blind Spot Monitor Master or Blind Spot Monitor Slave / Utility / BSM Master Abnormal History or BSM Slave Abnormal History.

Body Electrical > Blind Spot Monitor Master > Utility

Tester Display
BSM Master Abnormal History

Body Electrical > Blind Spot Monitor Slave > Utility

Tester Display
BSM Slave Abnormal History

(6) Check the results displayed for the abnormality history check.

Abnormality History Table

Tester Display	Item Explanation	Suspected Area
History of Module Blockage	History of blind spot monitor sensor detection problems due to snow, rain, etc. on the bumper	Check if a bumper that is not compatible with the blind spot monitor sensors (such as a non-genuine part) is installed Check if any foreign matter is attached to the bumper Check if any foreign matter is present between the bumper and sensors
History of Low Voltage	History of low supply battery voltage from battery to the blind spot monitor sensor	Power Source Circuit Click here
History of High Voltage	History of high supply battery voltage from battery to the blind spot monitor sensor
History of Low Temperature	History of low temperature for the blind spot monitor sensor	Check the outside temperature Check if any foreign matter is attached to the blind spot monitor sensors and their surrounding areas
History of High Temperature	History of high temperature for the blind spot monitor sensor

(b) Clearing abnormality history

(1) Connect the Techstream to the DLC3.

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

(3) Turn the Techstream on.

(4) Turn the blind spot monitor system on.

(5) Enter the following menus: Body Electrical / Blind Spot Monitor Master or Blind Spot Monitor Slave / Utility / BSM Master Abnormal History or BSM Slave Abnormal History.

Body Electrical > Blind Spot Monitor Master > Utility

Tester Display
BSM Master Abnormal History

Body Electrical > Blind Spot Monitor Slave > Utility

Tester Display
BSM Slave Abnormal History

(6) Clear the abnormality history.