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:
Diagnosis system
1. DIAGNOSIS FUNCTION
The diagnosis function makes the light and the
multi-information display come on, and the CRUISE
main indicator light blink as shown in the illustration.
When a malfunction occurs in the dynamic laser
cruise control system, the DTCs are stored in the
ECM ...
Disassembly
1. REMOVE REAR SEAT LEG COVER LH
Remove the 2 screws and seat leg cover.
2. REMOVE REAR SEAT LEG COVER RH
Remove the 2 screws and seat leg cover.
3. REMOVE REAR SEAT LEG SIDE COVER LH
Remove the 2 screws and leg side cover.
4. REMOVE LH SEAT REAR SEAT LOCK COVE ...
Display does not Dim when Light Control Switch is Turned ON
INSPECTION PROCEDURE
1 CHECK IMAGE QUALITY SETTING
Enter the display adjustment screen by pressing the
"DISPLAY" switch.
Turn the light control switch to the TAIL position.
Check if "DAY MODE" on the display adjustment is ON.
OK:
"DAY MODE" ...
