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:
How to proceed with
troubleshooting
HINT:
Use these procedures to troubleshoot the power folding
seat system.
*: Use the intelligent tester.
1 VEHICLE BROUGHT TO WORKSHOP
2 INSPECT BATTERY VOLTAGE
Standard voltage:
10 to 14 V
If the voltage is below 11 V, recharge or replace the battery
before proceeding.
...
Erasing the entire HomeLink® memory (all three programs)
Press and hold down the 2 outside
buttons for 10 seconds until
the indicator light flashes.
If you sell your vehicle, be sure to
erase the programs stored in the
HomeLink® memory.
Before programming
Install a new battery in the transmitter.
The battery side of the transmitter must ...
Oxygen (A/F) Sensor Signal Stuck
HINT:
Although the DTC titles say oxygen sensor, these DTCs relate to the
Air-Fuel Ratio (A/F) sensor.
Sensor 1 refers to the sensor mounted in front of the Three-Way
Catalytic Converter (TWC) and
located near the engine assembly.
DESCRIPTION
The A/F sensor generates a voltage* ...
