Toyota Sienna Service Manual: 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 of the rear evaporator temperature sensor changes in accordance with the rear evaporator temperature. As the temperature decreases, the resistance increases. As the temperature increases, the resistance decreases.
The A/C amplifier applies voltage (5 V) to the rear evaporator temperature
sensor and reads voltage
changes as the resistance of the rear evaporator temperature sensor changes.
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 EVAPORATOR TEMPERATURE SENSOR
(a) Remove the rear evaporator temperature sensor.
(b) Measure the resistance according to the value(s) in the table below.
Standard resistance 
NOTICE:
- Even slightly touching the sensor may change the resistance value. Be sure to hold the connector of the sensor.
- When measuring, the sensor temperature must be the same as the rear evaporator temperature.
HINT: As the temperature increases, the resistance decreases (see the graph).
3 CHECK HARNESS AND CONNECTOR (REAR EVAPORATOR TEMPERATURE SENSOR - A/C AMPLIFIER)
(a) Disconnect the rear evaporator temperature sensor connector.
(b) Disconnect the A/C amplifier connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard resistance 
REPLACE A/C AMPLIFIER
Evaporator temperature sensor circuit
DESCRIPTION
The evaporator temperature sensor (A/C thermistor) is installed on the
evaporator in the air conditioning
unit. It detects the temperature of the cooled air that has passed through the ...
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 R ...
Other materials:
Data list / active test
1. READ DATA LIST
HINT:
Using the intelligent tester's DATA LIST allows switch,
actuator and other item values to be read without
removing any parts. Reading the DATA LIST early in
troubleshooting is one way to save time.
Connect the intelligent tester with CAN VIM to the
DLC3.
&n ...
On-vehicle inspection
1. INSPECT CURTAIN SHIELD AIRBAG ASSEMBLY
(VEHICLE NOT INVOLVED IN COLLISION)
Perform a diagnostic system check.
With the curtain shield airbag assembly installed on
the vehicle, perform a visual check. If there are any
defects as mentioned below, replace the front pillar
...
For rear air conditioning system
ON-VEHICLE INSPECTION
1. INSPECT REAR AIR MIX CONTROL SERVO MOTOR
(a) Inspect servo motor operation.
(1) Connect the positive (+) lead from the battery
to terminal 4 and negative (-) lead to terminal 5,
then check that the arm turns to "HOT" side
smoothly.
(2) Connect the po ...
