Toyota Sienna Service Manual: Air Mix Damper Control Servo Motor Circuit (Driver Side)
DESCRIPTION
The air mix control servo motor (air mix damper servo sub-assembly) is controlled by the A/C amplifier.
The air mix control servo motor moves the air mix damper by rotating (normal, reverse) with electrical power from the A/C amplifier.
This adjusts the mix ratio of the air that passes through the evaporator and heater core and controls the air flow temperature. Air flow temperature changes when moving the air mix damper to the target point.
The target point can be detected by the air mix damper 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: When the target position is "MAX. COOL" (-5%), the actual opening angle is 19.0% or less.
When the target position is "MAX. HOT" (105%), the actual opening angle is 81.0% or more.
Result 
2 PERFORM ACTIVE TEST BY 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 item below in the ACTIVE TEST and then check the air flow temperature by hand.
ACTIVE TEST / AIR CONDITIONER 
OK: When the lever is moved to the "MAX. HOT" side, warm air comes out.
When the lever is moved to the "MAX. COOL" side, cool air comes out.
Result 
3 PERFORM ACTUATOR CHECK
(a) Enter the actuator check mode (See page AC-15).
(b) Press the DEF switch and change to the step operation.
(c) Check the air flow temperature by hand.
OK: Air flow temperature changes in accordance with each display code.
Result 
4 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) Connect the positive (+) lead from the battery to terminal 5 and the negative (-) lead to terminal 4, then check that the lever turns to the "MAX. HOT" position smoothly.
OK: Lever turns to "MAX. HOT" position smoothly.
(d) Connect the positive (+) lead from the battery to terminal 4 and the negative (-) lead to terminal 5, then check that the lever turns to the "MAX. COOL" position smoothly.
OK: Lever turns to "MAX. COOL" position smoothly.
5 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 Control Servo Motor Circuit
DESCRIPTION
This circuit turns the servo motor and changes each damper position by
receiving the signals from the A/
C amplifier.
The air outlet damper servo motor switches the air outlet mode ...
Rear Air Mix Damper Control Servo Motor Circuit
DESCRIPTION
The rear air mix control servo motor (water valve servo motor) is controlled
by the A/C amplifier.
The rear air mix control servo motor moves the air mix damper by rotating
(normal ...
Other materials:
Steering wheel audio
switches
Some audio features can be controlled using the switches on
the steering wheel.
Operation may differ depending on the type of audio system or
navigation system. For details, refer to the manual provided with
the audio system or navigation system.
Operating the audio system using the steering ...
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 ...
Unlock warning switch
INSPECTION
1. INSPECT UNLOCK WARNING SWITCH ASSEMBLY
Remove the unlock warning switch assembly .
Measure the resistance according to the value(s) in
the table below.
Standard resistance
...
