LEXUS PARKING ASSIST-SENSOR SYSTEM Clearance Warning Buzzer Circuit

DESCRIPTION

This circuit consists of a power source, the No. 1 clearance warning buzzer and clearance warning ECU assembly. An ECU-excited type buzzer is used. The auxiliary battery voltage supplied through the buzzer is grounded inside the clearance warning ECU using a pulsed digital pattern, producing sound. The ECU operates the buzzer using a sound pattern that changes depending on the distance to the obstacle.

WIRING DIAGRAM

A003XO6E01

INSPECTION PROCEDURE

Note

Inspect the fuses for circuits related to this system before performing the following inspection procedure.

PROCEDURE


  1. PERFORM ACTIVE TEST USING INTELLIGENT TESTER


    1. Connect the intelligent tester to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the LEXUS parking assist-sensor system on.

    4. Turn the intelligent tester on.

    5. Enter the following menus: Body / Clearance Sonar / Active Test.

    6. Check that the buzzer operates by performing the Active Test.

      Clearance Sonar
      Tester Display Test Part Control Range Diagnostic Note
      Buzzer No. 1 Clearance Warning Buzzer Operate or Stop Confirm that the vehicle is stopped and the power switch is on (IG)
      OK
      The No. 1 clearance warning buzzer sounds.

    NG

    CHECK HARNESS AND CONNECTOR (CLEARANCE WARNING BUZZER - AUXILIARY BATTERY) Click here

    OK

    PROCEED TO NEXT SUSPECTED AREA SHOWN IN PROBLEM SYMPTOMS TABLE Click here

  2. CHECK HARNESS AND CONNECTOR (CLEARANCE WARNING BUZZER - AUXILIARY BATTERY)


    1. Disconnect the H23 connector from the No. 1 Clearance Warning Buzzer.

    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Condition Specified Condition
      H23-1 (Z+) - Body ground Power switch on (IG) 11 to 14 V
      H23-1 (Z+) - Body ground Power switch off Below 1 V

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. CHECK HARNESS AND CONNECTOR (CLEARANCE WARNING ECU ASSEMBLY - CLEARANCE WARNING BUZZER)


    1. Disconnect the A49 connector from the clearance warning ECU assembly.

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

      Standard Resistance
      Tester Connection Condition Specified Condition
      A49-12 (CBZ) - H23-2 (Z-) Always Below 1 Ω
      A49-12 (CBZ) - Body ground Always 10 kΩ or higher

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. REPLACE NO. 1 CLEARANCE WARNING BUZZER


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


    NEXT

  5. PERFORM ACTIVE TEST USING INTELLIGENT TESTER


    1. Connect the intelligent tester to the DLC3.

    2. Turn the power switch on (IG).

    3. Turn the LEXUS parking assist-sensor system on.

    4. Turn the intelligent tester on.

    5. Enter the following menus: Body / Clearance Sonar / Active Test.

    6. Check that the buzzer operates by performing the Active Test.

      Clearance Sonar
      Tester Display Test Part Control Range Diagnostic Note
      Buzzer No. 1 clearance warning buzzer Operate or Stop Confirm that the vehicle is stopped and the power switch is on (IG)
      OK
      The No. 1 clearance warning buzzer sounds.

    NG

    REPLACE CLEARANCE WARNING ECU ASSEMBLY Click here

    OK

    END (CLEARANCE WARNING BUZZER WAS DEFECTIVE)