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. DESCRIPTION
When troubleshooting a vehicle with the diagnosis
system, the only difference from the usual
troubleshooting procedure is connecting the intelligent
tester to the vehicle and reading various data output from
the vehicle's clearance warning ECU.
The clearance warning ECU record ...
Installation
1. INSTALL STEERING ANGLE SENSOR
(a) Install the steering sensor onto the spiral cable.
2. PLACE FRONT WHEELS FACING STRAIGHT AHEAD
3. INSTALL SPIRAL CABLE SUB-ASSEMBLY (See page
RS-434)
4. INSTALL STEERING COLUMN COVER LWR (See
page RS-435)
5. CENTER SPIRAL CABLE (See page RS-435)
6. IN ...
Communication Error of Yaw Rate Sensor
DTC U0123 Communication Error of Yaw Rate Sensor
DESCRIPTION
This circuit detects the yaw rate of the vehicle and transmits its signal to
the skid control ECU and
distance control ECU.
DTC No.
DTC Detection Condition
Trouble Area
U0123
While the dynamic ...