Toyota Sienna Service Manual: Room Temperature Sensor Circuit
DESCRIPTION
This sensor detects the cabin temperature that is used as the basis for
temperature control and sends a
signal to the A/C amplifier. 
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 item 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 A/C ROOM TEMPERATURE SENSOR
(a) Remove the A/C room temperature sensor.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance 
NOTICE:
- Hold the sensor only by its connector. Touching the sensor may change the resistance value.
- When measuring, the sensor temperature must be the same as the room temperature.
HINT: As the temperature increases, the resistance decreases (see the graph).
3 CHECK HARNESS AND CONNECTOR (A/C ROOM TEMPERATURE SENSOR - A/C AMPLIFIER)
(a) Disconnect the connector from the A/C amplifier.
(b) Disconnect the connector from the A/C room temperature sensor.
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance 
REPLACE A/C AMPLIFIER
Actuator check
1. ACTUATOR CHECK
(a) After entering the DTC check mode (Sensor Check
Mode), press the R/F switch.
(b) As each damper, motor and relay automatically
operate actuator check at 1-second interval ...
Ambient temperature sensor circuit
DTC B1412/12 Ambient Temperature Sensor Circuit
DESCRIPTION
The ambient temperature sensor is installed in front of the condenser to
detect the ambient temperature
which is used to control the ai ...
Other materials:
Inspection and adjustment procedure
Tire valve
Tire pressure gauge
Remove the tire valve cap.
Press the tip of the tire pressure gauge onto the tire valve.
Read the pressure using the gauge gradations.
If the tire inflation pressure is not at the recommended level, adjust
the pressure.
If you add too much air, ...
Removal
1. REMOVE REAR SEAT LEG SIDE GARNISH SUBASSEMBLY LH
Disengage the clips and remove the seat leg side
garnish.
2. REMOVE REAR NO. 2 SEAT ASSEMBLY LH
Remove the bolt and locus cable.
Remove the 2 bolts and seat.
Remove the 2 headrests.
...
On-vehicle inspection
1. CONNECT INTELLIGENT TESTER
(a) Connect the intelligent tester to the DLC3.
(b) Start the engine and run at idle.
(c) Select the ACTIVE TEST mode on the intelligent
tester.
HINT:
Please refer to the intelligent tester operator's
manual for further details.
2. INSPECT ACTUATOR MOTOR ...
