Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual: Lost Communication with Image Processing Module "A" Missing Message (U023A87)

DESCRIPTION

The forward recognition camera communicates with the skid control ECU (brake actuator assembly) via CAN communication.

If a communication error is detected between the skid control ECU (brake actuator assembly) and forward recognition camera, the forward recognition camera stores this DTC.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area
U023A87	Lost Communication with Image Processing Module "A" Missing Message	When the engine switch is on (IG) for 2 seconds or more, a communication malfunction between the skid control ECU (brake actuator assembly) the forward recognition camera is detected for 3 seconds or more.	Vehicle stability control system Forward recognition camera

CAUTION / NOTICE / HINT

PROCEDURE

1.	CHECK FOR DTCs

(a) Using the Techstream, check for vehicle stability control system DTCs.

Chassis > Brake/EPB > Trouble Codes

HINT:

If DTC U023A87 and vehicle stability control system DTCs are output, perform troubleshooting for the vehicle stability control system first.

Result	Proceed to
Vehicle stability control system DTCs are not output	A
Vehicle stability control system DTCs are output	B

B

GO TO VEHICLE STABILITY CONTROL SYSTEM

A

2.	PERFORM DEALER MODE (SIGNAL CHECK) (ELECTRONICALLY CONTROLLED BRAKE SYSTEM)

HINT:

When entering Dealer Mode (Signal Check), the skid control ECU communicates with the forward recognition camera to judge whether the vehicle is equipped with the pre-collision system. Therefore, do not exit Dealer Mode (Signal Check) within 5 seconds of entering Dealer Mode (Signal Check).

(a) Procedure to enter Dealer Mode (Signal Check)

(1) Turn the engine switch off.

(2) Apply the parking brake.

(3) Check that the shift lever is in P.

(4) Connect the Techstream to the DLC3.

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

(6) Check that the steering wheel is centered.

(7) Turn the Techstream on.

(8) Enter the following menus: Chassis / Brake/EPB / Utility / Signal Check.

Chassis > Brake/EPB > Utility

Tester Display
Signal Check

HINT:

Do not exit Dealer Mode (Signal Check) within 5 seconds of entering Dealer Mode (Signal Check). If Dealer Mode (Signal Check) is exited within 5 seconds of entering Dealer Mode (Signal Check), DTC U023A87 may be stored. If DTC U023A87 is output after exiting Dealer Mode (Signal Check), enter Dealer Mode (Signal Check) again, wait at least 5 seconds, then recheck for DTCs.

(b) Confirm the system has entered Dealer Mode (Signal Check).

(1) Confirm that the ABS warning light and slip indicator light indicate the Dealer Mode pattern (blinking at 0.25 second intervals).

(c) End of Dealer Mode (Signal Check)

(1) Turn the engine switch off.

(2) Disconnect the Techstream.

NEXT

3.	CHECK FOR DTCs

(a) Clear the DTCs.

Body Electrical > Pre-Collision System > Clear DTCs

(b) Make sure that the DTC detection conditions are met.

HINT:

If the detection conditions are not met, the system cannot detect the malfunction.

(c) Check for DTCs.

Body Electrical > Pre-Collision System > Trouble Codes

Result	Proceed to
DTC U023A87 is not output	A
DTC U023A87 is output	B

A

END

B

REPLACE FORWARD RECOGNITION CAMERA