Toyota Sienna Service Manual: 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 air mix control servo motor. The position sensor resistance changes as the air mix control servo motor arm moves.
It outputs voltage (5 V) that is input to terminal 1 and terminal 3 via the
variable resistor, and then to the A/
C amplifier. The A/C amplifier determines the arm 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 AIR MIX CONTROL SERVO MOTOR
(a) Remove the air mix control servo motor.
(b) Disconnect the connector from the air mix control 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.
Standard resistance 
(e) As the air mix control servo motor moves from the COOL side to the HOT side, the resistance decreases gradually without interruption.
3 CHECK HARNESS AND CONNECTOR (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 Outlet Damper Position Sensor Circuit
DESCRIPTION
This sensor detects the position of the air outlet control servo motor and
sends the appropriate signals to
the A/C amplifier. The position sensor is built in the air outlet contro ...
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 bu ...
Other materials:
Diagnosis system
1. CHECK DLC3
The ECU uses the ISO 15765-4 for communication
protocol. The terminal arrangement of the DLC3
complies with SAE J1962 and matches the ISO
15765-4 format.
NOTICE:
*: Before measuring the resistance, leave the
vehicle as is for at least 1 minute and do not
ope ...
Problem symptoms table
HINT:
Proceed to the troubleshooting for each circuit in the table
below.
AIRBAG SYSTEM
Symptom
Suspected Area
The SRS warning light goes off after the primary
check, but then comes on.
SRS Warning Light Remains ON
When the ignition switch is turned to t ...
Problem symptoms table
HINT:
Use the table below to help determine the cause of the
problem symptom. The potential causes of the symptoms
are listed in order of probability in the "Suspected Area"
column of the table. Check each symptom by checking the
suspected areas in the order they are listed. Re ...
