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:
Occupant Classification ECU Malfunction
DTC B1795 Occupant Classification ECU Malfunction
DESCRIPTION
DTC B1795 is recorded when a malfunction is detected in the occupant
classification ECU.
Troubleshoot DTC B1771 first when the DTCs B1771 and B1795 are output
simultaneously.
WIRING DIAGRAM
INSPECTION PROCEDURE
1 CHECK DTC ...
Customize parameters
1. CUSTOMIZING FUNCTION WITH INTELLIGENT
TESTER (REFERENCE)
HINT:
The following items can be customized.
NOTICE:
After confirming whether the items requested by
the customer are applicable or not for
customization, perform customize operations.
Be sure to record the current ...
Poor Sound Quality in All Modes (Low Volume)
INSPECTION PROCEDURE
1 CHECK AUDIO SETTINGS
Set "BASS", "MID" and "TREB" to the initial values and
check that sound is normal.
OK:
Malfunction disappears.
2 COMPARE WITH ANOTHER VEHICLE OF SAME MODEL
Compare with another vehicle of the same model.
...
