Toyota Sienna Service Manual: Rear Air Mix Damper Position Sensor Circuit
DESCRIPTION
This sensor detects the position of the rear air mix control servo motor (water valve servo motor) and sends the appropriate signals to the A/C amplifier. The position sensor is built in the rear air mix control servo motor (water valve servo motor).
The position sensor's resistance changes as the rear air mix control servo motor valve moves.
It outputs voltage (5 V) that is input to terminal 2 and terminal 3 via the variable resistor, and then to the A/ C amplifier.
The A/C amplifier determines the valve position based on the input voltage from
the position sensor.
WIRING DIAGRAM
INSPECTION PROCEDURE
1 READ VALUE OF INTELLIGENT TESTER
(a) Connect the intelligent tester to the DLC3.
(b) Turn the ignition switch to the ON position and turn the intelligent tester main switch on.
(c) Select the items below in the DATA LIST, and read the display on the intelligent tester.
DATA LIST / AIR CONDITIONER 
OK: The display is as specified in the normal condition column.
Result 
2 INSPECT REAR AIR MIX CONTROL SERVO MOTOR (WATER VALVE SERVO MOTOR)
(a) Remove the rear air mix control servo motor (water valve servo motor).
(b) Disconnect the connector from the rear air mix control servo motor (water valve servo motor).
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance
(d) Measure the resistance according to the value(s) in the table below.
HINT
- In order to turn the motor to the "MAX. COOL" position, connect the positive (+) lead to terminal 5, and the negative (-) lead to terminal 4.
- In order to turn the motor to the "MAX. HOT" position, connect the positive (+) lead to terminal 4, and the negative (-) lead to terminal 5.
Standard resistance 
(e) As the rear air mix control servo motor (water valve servo motor) moves from the cool side to the hot side, the resistance decreases gradually without interruption.
3 CHECK HARNESS AND CONNECTOR (REAR AIR MIX CONTROL SERVO MOTOR - A/C AMPLIFIER)
(a) Disconnect the connector from the A/C amplifier.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance 
REPLACE A/C AMPLIFIER
Air Mix Damper Position Sensor Circuit (Driver Side)
DESCRIPTION
This sensor detects the position of the air mix control servo motor (air
outlet damper) and sends the
appropriate signals to the A/C amplifier. The position sensor is built in the ...
Rear Air Outlet Damper Position Sensor Circuit
DESCRIPTION
This sensor detects the position of the rear air outlet control servo motor
and sends the appropriate
signals to the A/C amplifier. The position sensor is built in the rear air
o ...
Other materials:
Disposal
HINT:
When scrapping a vehicle equipped with the SRS or
disposing of the steering pad, be sure to deploy the airbag
first in accordance with the procedure described below. If any
abnormality occurs with airbag deployment, contact the
SERVICE DEPT. of TOYOTA MOTOR SALES, U.S.A., INC.
CAUTION:
...
Back-up Power Source Circuit
DESCRIPTION
This is the back-up power source for the A/C amplifier. Power is supplied
even when the ignition switch is
off and is used for diagnostic trouble code memory, etc.
WIRING DIAGRAM
INSPECTION PROCEDURE
1 INSPECT FUSE (ECU-B)
(a) Remove the ECU-B fuse from the engine room juncti ...
Optimal use of the audio
system
On the “Sound Settings” screen, sound quality (Treble/Mid/
Bass), volume balance can be adjusted.
How to adjust the sound settings and sound quality
1, 2, 3 Select “-” or “+” to adjust
the treble, mid or bass to
a level between -5 and 5.
4, 5 Select “Front” or “Rear” ...
