Lexus ES: System Description

SYSTEM DESCRIPTION

GENERAL

(a) The parking support alert system has a static objects function, rear crossing vehicles function, and rear pedestrians.

FUNCTION OF COMPONENTS

OPERATION DESCRIPTION (PARKING SUPPORT ALERT [STATIC OBJECTS] FUNCTION)

(a) The operating conditions of each ultrasonic sensor differ according to their installation position, as shown in the table below.

When the system operates, the clearance warning ECU assembly transmits ultrasonic waves from the ultrasonic sensors. If these waves encounter an obstacle within the range of one or more of the sensors, the waves are reflected back to the sensors, which transmit them to the clearance warning ECU assembly.

Based on this information, the clearance warning ECU assembly sends signals to the radio receiver assembly, the combination meter assembly and the No. 1 clearance warning buzzer and No. 2 clearance warning buzzer. The approximate distance between the vehicle and the obstacle is then indicated, and the buzzers sound.

HINT:

Refer to Detection Range Measurement and Display Inspection.

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COMMUNICATION SIGNALS OF COMPONENTS (PARKING SUPPORT ALERT [STATIC OBJECTS] FUNCTION)

(a) Initialization mode:

An ID is allocated to each sensor and sensor diagnosis is performed.

(1) When the initial check is performed (the engine switch is on (IG) and the static objects function is on), the clearance warning ECU assembly provides power to the first sensor in each series (front corner ultrasonic sensor RH and rear corner ultrasonic sensor RH).

(2) After the power is supplied, the front corner ultrasonic sensor RH and rear corner ultrasonic sensor RH enter standby mode to receive an ID from the ECU. When a certain amount of time has elapsed, the ECU sends an ID allocation signal to these sensors.

(3) The front corner ultrasonic sensor RH and rear corner ultrasonic sensor RH receive the ID allocation signal from the ECU and perform self-diagnosis. When the sensor self-diagnosis is complete, the ECU sends an ID allocation confirmation signal to the sensors.

(4) After the ID allocation confirmation is performed, the ECU provides power to the second sensor in each series (front center ultrasonic sensor RH and rear center ultrasonic sensor RH) via the first sensor. In the same manner as the first sensors, the second sensor enter standby mode. When a certain amount of time has elapsed, the ECU sends an ID allocation signal to the second sensors.

(5) The above operation will be repeated until an ID is allocated to the last sensor (front corner ultrasonic sensor LH or rear corner ultrasonic sensor LH). Initialization ends when ID allocation to all ultrasonic sensors is completed.

(b) Detection mode:

After initialization is completed, the system changes to detection mode. In detection mode, the clearance warning ECU assembly sends information request signals and sensor activation signals to the ultrasonic sensors and receives detection result signals from the sensors.

(1) The ECU regularly sends ID signals, information request signals, and sensor activation signals to each ultrasonic sensor according to the communication schedule.

(2) When a certain amount of time has elapsed (sensor detection operation is completed), the ECU sends an ID signal to the sensor to receive a detection result signal.

(3) The ultrasonic sensor sends a detection result signal or detection information signal to the ECU.

(4) The above operation is performed repeatedly for each ultrasonic sensor.

OPERATION DESCRIPTION (PARKING SUPPORT ALERT [REAR CROSSING VEHICLES] FUNCTION)

(a) Operation description of the RCTA function

(1) Operation conditions:

(2) Conditions in which a sensor can detect a vehicle

The RCTA function indicates detection of a vehicle in the detection area when both conditions are met:

(3) Detection area

Vehicles in the following areas can be detected:

*a	Within approximately 5.5 to 20 m (18.04 to 65.6 ft.) from side of vehicle (detection area changes according to vehicle speed)
*b	Within approximately 6 m (19.68 ft.) behind rear bumper
	Detection Area

OPERATION OF OUTER REAR VIEW MIRROR INDICATOR AND RCTA BUZZER (BLIND SPOT MONITOR BUZZER) (PARKING SUPPORT ALERT [REAR CROSSING VEHICLES] FUNCTION)

(a) Initial check

(1) When the RCTA function is turned on with the engine switch on (IG), the outer rear view mirror indicators on the outer rear view mirror assembly illuminate for 3 seconds and the RCTA buzzer (blind spot monitor buzzer) sounds for 1 second.

(2) When the engine switch is turned from off to on (IG) with the blind spot monitor system on, the outer rear view mirror indicators on the outer rear view mirror assembly illuminate for 3 seconds.

(b) Operation for each function

(1) Operation for RCTA function

RCTA ICON OUTLINE

(a) If a vehicle approaching from the right or left at the rear of the vehicle is detected, the icon will illuminate on the multi-display.

OPERATION DESCRIPTION (PARKING SUPPORT ALERT [REAR PEDESTRIAN DETECTION] FUNCTION)

(a) Operation description of the rear camera detection function

(1) Operation conditions:

(2) Detection Area

*a	Detection Area
	Detection Area A
	Detection Area B
	Detection Area C

(b) Rear camera detection function screen

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