Lexus RX (RX 350L, RX450h) 2016-2025 Repair Manual: Front Left Sensor Malfunction (C1AE1)

DESCRIPTION

The front corner ultrasonic sensor LH is installed to the front bumper. The clearance warning ECU assembly detects obstacles based on signals received from the front corner ultrasonic sensor LH. If the front corner ultrasonic sensor LH has an open circuit or other malfunction, it will not function normally.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area
C1AE1	Front Left Sensor Malfunction	A malfunction of the front corner ultrasonic sensor LH.	Front corner ultrasonic sensor LH Clearance warning ECU assembly

CAUTION / NOTICE / HINT

NOTICE:

If DTCs are output after repairs, turn the engine switch on (IG) and the intuitive parking assist system on. Then clear the DTCs.

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PROCEDURE

1.	CHECK DTC OUTPUT

(a) Check for DTCs.

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Body Electrical > Advanced Parking Guidance/ICS/Intuitive P/A > Trouble Codes

Result	Proceed to
Only DTC C1AE1 is output	A
DTC C1AE1 and C1AEC are output	B
No DTCs are output	C

B

GO TO DTC (C1AEC)

C

USE SIMULATION METHOD TO CHECK

A

2.	REPLACE FRONT CORNER ULTRASONIC SENSOR LH

(a) Replace the front corner ultrasonic sensor LH with a known good one.

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HINT:

All of the sensors are interchangeable. To confirm whether a sensor is functioning normally, switch it with a known good sensor from the other end of the vehicle.

NEXT

3.	CHECK DTC OUTPUT

(a) Clear the DTCs.

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Body Electrical > Advanced Parking Guidance/ICS/Intuitive P/A > Clear DTCs

(b) Check for DTCs.

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Body Electrical > Advanced Parking Guidance/ICS/Intuitive P/A > Trouble Codes

Result	Proceed to
DTC C1AE1 is output	A
No DTCs are output	B

A

REPLACE CLEARANCE WARNING ECU ASSEMBLY

B

END (FRONT LEFT SENSOR WAS DEFECTIVE)