Toyota Sienna Service Manual: Rear Room Temperature Sensor Circuit
DESCRIPTION
This sensor detects the rear 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 REAR A/C ROOM TEMPERATURE SENSOR
(a) Remove the rear 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 rear cabin temperature.
HINT: As the temperature increases, the resistance decreases (see the graph).
3 CHECK HARNESS AND CONNECTOR (REAR A/C ROOM TEMPERATURE SENSOR - A/C AMPLIFIER)
(a) Disconnect the connector from the A/C amplifier.
(b) Disconnect the connector from the rear A/C room temperature sensor.
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance 
REPLACE A/C AMPLIFIER
Rear evaporator temperature sensor circuit
DESCRIPTION
The rear evaporator temperature sensor is installed on the rear evaporator.
It detects the rear evaporator
temperature. The sensor sends a signal to the A/C amplifier. The resistance o ...
Solar Sensor Circuit (Passenger Side)
DTC B1421/21 Solar Sensor Circuit (Passenger Side)
DESCRIPTION
The solar sensor, which is installed on the upper side of the instrument
panel, detects sunlight and
controls the air conditioni ...
Other materials:
Data list / active test
1. DATA LIST
Using the intelligent tester to read the Data List allows
the values or states of switches, sensors, actuators and
other items to be read without removing any parts. This
non-intrusive inspection can be very useful because
intermittent conditions or signals may be discovered
befor ...
Electronic control
(a) REMOVAL AND INSTALLATION OF BATTERY TERMINAL
REMOVAL AND INSTALLATION OF BATTERY TERMINAL
NOTICE: Certain systems need to be initialized
after
disconnecting and reconnecting the cable from
the negative (-) battery terminal.
(1) Before performing electronic work, disconnect
the ...
Inspection
1. Inspect starter assembly
NOTICE:
These tests must be performed within 3 to 5 seconds
to avoid burning out the coil.
(a) Perform the pull-in test.
(1) Disconnect the lead wire from terminal C.
(2) Connect the battery to the magnetic switch as
shown in the illustratio ...
