Toyota Sienna Service Manual: No. 1 Clearance Warning Buzzer Circuit
DESCRIPTION
The clearance warning ECU receives the ultrasonic sensor signal to sound the front warning buzzer.
WIRING DIAGRAM
INSPECTION PROCEDURE
1 INSPECT FRONT BUZZER
- Remove the clearance warning ECU with front buzzer.
- Apply the battery voltage to the terminals 1 and 2 of the buzzer, and check that the buzzer sounds.
HINT: The clearance warning buzzer is separately excited, and will not sound unless an alternating voltage is applied.
OK: Operating noise (clicking sounds) can be heard.
2 CHECK HARNESS AND CONNECTOR (CLEARANCE WARNING ECU - FRONT BUZZER)
- Disconnect the clearance warning ECU connector and front buzzer connector.
- Measure the resistance according to the value(s) in the table below.
Standard resistance
PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
Rear Clearance Sonar Sensor RH Circuit
DESCRIPTION
An ultrasonic sensor consists of a sensor portion that transmits and receives
ultrasonic waves and a preamplifier
that amplifies them. The ultrasonic sensor outputs the ultrasonic wave ...
Clearance Warning ECU Power Source Circuit
DESCRIPTION
This circuit provides power to the clearance warning ECU.
WIRING DIAGRAM
INSPECTION PROCEDURE
1 CHECK HARNESS AND CONNECTOR (CLEARANCE WARNING ECU - AIR CONDITIONER
AMPLIFIER)
...
Other materials:
How to proceed with
troubleshooting
HINT:
Use this procedure to troubleshoot the front power seat
control system.
The intelligent tester should be used in steps 3 and 5.
1 VEHICLE BROUGHT TO WORKSHOP
2 CUSTOMER PROBLEM ANALYSIS CHECK AND PROBLEM SYMPTOM CHECK
3 CHECK COMMUNICATION FUNCTION OF MULTIPLEX COMMUNI ...
Purpose of readiness tests
The On-Board Diagnostic (OBD II) system is
designed to monitor the performance of emissionrelated
components, and indicate any detected
abnormalities with DTCs (Diagnostic Trouble Codes).
Since various components need to be monitored in
different driving conditions, the OBD II system ...
Problem symptoms table
HINT:
Proceed to troubleshooting of each circuit in the table below.
1. HEADLIGHT AND TAIL LIGHT SYSTEM
2. AUTOMATIC LIGHT CONTROL SYSTEM
3. LIGHT AUTO TURN OFF SYSTEM
4. FOG LIGHT SYSTEM
5. TURN SIGNAL AND HAZARD WARNING SYSTEM
6. ILLUMINATED ENTRY SYSTEM
7. OTHE ...
