No. 1 Clearance Warning Buzzer Circuit

WIRING DIAGRAM

INSPECTION PROCEDURE

1. PERFORM ACTIVE TEST BY INTELLIGENT TESTER

1. Connect the intelligent tester to the DLC3.

2. Turn the engine switch ON (IG).

3. Turn the intelligent tester main switch ON.

4. Turn the clearance sonar main switch ON.

5. Select the Active Test, use the intelligent tester to generate a control command, and then check that the buzzer operates.

   Clearance warning ECU:  

   Item	Vehicle Condition / Test Details	Diagnostic Note
   REAR BUZZER	Rear buzzer (Clearance warning buzzer) / STOP or OPERATE	-

   OK:

   No. 1 clearance warning buzzer sounds.
   

OK	PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE

NG

2. CHECK WIRE HARNESS (NO. 1 CLEARANCE WARNING BUZZER - CLEARANCE WARNING ECU)

1. Disconnect the Q37 ECU connector.

2. Disconnect the J39 buzzer connector.

3. Measure the resistance of the wire harness side connectors.

   Standard resistance:

   Tester Connection	Condition	Specified Condition
   CBZ (Q37-9) - J39-2	Always	Below 1 Ω
   CBZ (Q37-9) - Body ground	Always	10 kΩ or higher

NG	REPAIR OR REPLACE HARNESS OR CONNECTOR

OK

3. CHECK NO. 1 CLEARANCE WARNING BUZZER (TERMINAL VOLTAGE)

1. Disconnect the J39 buzzer connector.

2. Measure the voltage of the connector.

   Standard voltage:

   Tester Connection	Condition	Specified Condition
   J39-1 - Body ground	Engine switch ON (IG)	10 to 14 V

NG	REPAIR OR REPLACE HARNESS OR CONNECTOR (NO. 1 CLEARANCE WARNING BUZZER - BATTERY)

OK

4. INSPECT NO. 1 CLEARANCE WARNING BUZZER

1. Apply battery voltage and check operation of the warning buzzer, as shown in the table.

   Measurement Condition	Specified Condition
   Battery positive (+) → J39-1 Battery negative (-) → J39-2	Operating sound occurs

   HINT:

   The clearance warning buzzer does not sound without battery voltage applied because the buzzer is a separately-excited type.

NG	REPLACE NO. 1 CLEARANCE WARNING BUZZER

OK
REPLACE CLEARANCE WARNING ECU ASSEMBLY