Toyota Prius 3rd Gen No. 1 Ultrasonic Sensor LH Assembly

Toyota Prius 3 ^rd Generation (XW30)

No. 1 Ultrasonic Sensor LH Assembly Wiring Guide: DIY Pinout Diagram

What is: The Vehicle No. 1 Ultrasonic Sensor LH Assembly is a left-hand side parking assist sensor mounted on the front or rear bumper. It uses ultrasonic waves to detect nearby obstacles and measure distance during low-speed maneuvers. The sensor sends signals to the parking assist ECU, helping provide audible or visual warnings to the driver for safer parking and collision avoidance.

No. 1 Ultrasonic Sensor LH Assembly (89341-48040-B6)

Left-hand ultrasonic sensor for low-speed obstacle detection in Prius 3rd gen

Vehicle parking assist system component: Prius No. 1 ultrasonic sensor LH

Close-up of No. 1 Ultrasonic Sensor LH Assembly 89341-48040-B6

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1. Introduction

      The  Toyota Prius 3rd Generation No. 1 Ultrasonic Sensor LH Assembly (89341-48040-B6) is a key component of the vehicle’s parking assist system, designed to enhance safety and driver awareness. Mounted on the left-hand side of the bumper, it emits ultrasonic waves to detect nearby obstacles during low-speed maneuvers. The sensor accurately measures distance and sends real-time signals to the parking assist ECU for processing. This enables audible beeps or visual alerts to warn the driver. Built for reliability, it performs effectively in tight parking spaces, reducing collision risks and improving overall convenience, especially in urban driving conditions. No. 1 Ultrasonic Sensor LH Assembly (89341-48040-B6) is a key component of the vehicle’s parking assist system, designed to enhance safety and driver awareness. Mounted on the left-hand side of the bumper, it emits ultrasonic waves to detect nearby obstacles during low-speed maneuvers. The sensor accurately measures distance and sends real-time signals to the parking assist ECU for processing. This enables audible beeps or visual alerts to warn the driver. Built for reliability, it performs effectively in tight parking spaces, reducing collision risks and improving overall convenience, especially in urban driving conditions.

Related parts and Accessories

• Parking Assist ECU (Clearance Warning ECU):-Processes signals from all ultrasonic sensors and determines obstacle distance.
• Other Ultrasonic Sensors (Front/Rear – RH & LH) :-Work together to provide full vehicle coverage.
• Combination Meter / Multi-Information Display :-Shows visual distance indicators and warnings.
• Buzzer / Warning Speaker:-Produces audible alerts based on proximity.
• Shift Position Sensor:-Detects gear (Reverse/Drive) to activate the system.
• Brake ECU / Vehicle Speed Sensor:-Ensures operation during low-speed conditions.
• Main Body ECU:-Supports system coordination and communication.

2. No. 1 Ultrasonic Sensor LH Assembly Wiring Diagram & Pinout

A. Connector Location

• No. 1 Ultrasonic Sensor LH Assembly Position: The No. 1 Ultrasonic Sensor LH Assembly is mounted on the left front bumper corner, flush with the surface for obstacle detection.


• Connector Type:
  • C2 (6 pin) Black housing

B. Wiring Table

No. 1 Ultrasonic Sensor LH (C2)

C2 TERMINALS OF NO. 1 ULTRASONIC SENSOR LH CONNECTOR

Terminal No	Symbol	Wiring (Color Code) & Color	Electrical Paths
C2-1	B1	(G) Green	➔ CA1 7 ➳ AL2 19 ➳ L64 19 (CSB3) ➤ [Parking Assist ECU]
C2-2	BO	(Y) Yellow	➔ C1 1 (BI) ➤ [No. 1 Ultrasonic Sensor RH]
C2-3	SI	(GR) Gray	➔ CA1 4 ➳ AL2 20 ➳ L64 21 (LIN3) ➤ [Parking Assist ECU]
C2-4	SO	(L) Blue	➔ C1 3 (SI) ➤ [No. 1 Ultrasonic Sensor RH]
C2-5	E1	(R) Red	➔ CA1 3 ➳ AL2 21 ➳ L64 20 (CSG3) ➤ [Parking Assist ECU]
C2-6	EO	(BR) Brown	➔ C1 5 (EI) ➤ [No. 1 Ultrasonic Sensor RH]

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Quick Pin Summary – C2 Connector

Connector: C2 (6-pin, Black housing)

• C2-1 B1 (Sensor Power / Control Signal) :
  Supplies operating power and communication reference for the sensor. Used by the system to activate and manage ultrasonic signal processing.
• C2-2 BO (Bus Output to RH Sensor) :
  Transfers signal data from LH sensor to the RH ultrasonic sensor. Enables communication link between paired sensors for coordinated detection.
• C2-3 SI (Signal Input / LIN Communication) :
  Receives control and communication signals from the ECU. Used for data exchange via LIN bus for accurate distance calculation.
• C2-4 SO (Signal Output to RH Sensor) :
  Sends processed signal data to the RH sensor. Supports synchronized operation between left and right sensors.
• C2-5 E1 (Ground / Earth) :
  Provides electrical grounding for stable sensor operation. Ensures proper circuit completion and noise reduction.
• C2-6 EO (Earth Output to RH Sensor) :
  Shares ground reference with the RH ultrasonic sensor. Maintains consistent grounding across sensor network.

Quick Note:The C2 connector of the No. 1 Ultrasonic Sensor LH supplies power, ground, and LIN communication with the Parking Assist ECU while linking signals to the RH sensor for synchronized obstacle detection.