TOYOTA PARKING ASSIST-SENSOR SYSTEM Clearance Warning Buzzer Circuit

DESCRIPTION

This circuit consists of the No. 1 clearance warning buzzer and clearance warning ECU assembly. An ECU-excited type buzzer is used. The ECU operates the buzzer using a sound pattern that changes depending on the distance to an obstacle.

WIRING DIAGRAM

B003LOUE01
*a No. 1 Clearance Warning Buzzer
*b Clearance Warning ECU Assembly

PROCEDURE


  1. CHECK CLEARANCE WARNING ECU ASSEMBLY (BUZZER CIRCUIT)


    1. Remove the clearance warning ECU assembly with its connectors still connected.

      B003J44C01
      *a

      Component with harness connected

      (Clearance Warning ECU Assembly)

      		 *b Waveform

    2. Check the waveform of the clearance warning ECU assembly using an oscilloscope.

      Item Content
      Terminal No. (Symbol) G88-2 (ER) - Body ground
      Tool Setting 2 V/DIV., 200 μsec./DIV.
      Condition When sonar detects obstacle (buzzer sounds)
      OK
      Waveform is as shown in the illustration.
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE CLEARANCE WARNING ECU ASSEMBLY Click here

    NG

  2. CHECK HARNESS AND CONNECTOR (CLEARANCE WARNING ECU ASSEMBLY - NO. 1 CLEARANCE WARNING BUZZER)


    1. Disconnect the G88 clearance warning ECU assembly connector.

    2. Disconnect the G86 No. 1 clearance warning buzzer connector.

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      G88-1 (BBZ) - G86-1 (Z+) Always Below 1 Ω
      G88-2 (ER) - G86-2 (Z-) Always Below 1 Ω
      G88-1 (BBZ) or G86-1 (Z+) - Body ground Always 10 kΩ or higher
      G88-2 (ER) or G86-2 (Z-) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. CHECK NO. 1 CLEARANCE WARNING BUZZER


    1. Replace the No. 1 clearance warning buzzer with a new or known good one.

      Click here

    2. Check if the same malfunction recurs when the sonar function is operated.

      OK
      Malfunction does not reoccur (returns to normal).
      Result
      Proceed to
      OK
      NG

    OK

    END (NO. 1 CLEARANCE WARNING BUZZER WAS DEFECTIVE)

    NG

    REPLACE CLEARANCE WARNING ECU ASSEMBLY Click here