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:
Heater relay (for rear air conditioning system)
ON-VEHICLE INSPECTION
1. INSPECT REAR HEATER RELAY
(a) Remove the rear heater relay.
(b) Measure the resistance according to the value(s) in
the table below.
Standard resistance
If the resistance is not as specified, replace the rear
heater relay. ...
Engine Control System Malfunction
DTC C1201/51 Engine Control System Malfunction
DESCRIPTION
If trouble occurs the engine control system, the ECM transmits the
abnormality to the skid control ECU.
The skid control ECU set this DTC and the skid control ECU prohibits TRAC and
VSC control.
INSPECTION PROCEDURE
1 CHECK ENGIN ...
Air Inlet Damper Position Sensor Circuit
DESCRIPTION
This sensor detects the position of the air inlet control servo motor and
sends the appropriate signals to
the A/C amplifier. The position sensor is built in the air inlet control servo
motor.
The position sensor's resistance changes as the air inlet control servo motor
ar ...
