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:
Seat Belt Buckle Switch LH Circuit Malfunction
DTC B0126/27 Seat Belt Buckle Switch LH Circuit Malfunction
DESCRIPTION
The seat belt buckle switch LH circuit consists of the center airbag sensor
assembly and the front seat
inner belt assembly LH.
DTC B0126/27 is recorded when a malfunction is detected in the seat belt buckle
switch LH ...
Precaution
1. REMOVAL AND INSTALLATION OF THE BATTERY TERMINAL
Before performing electrical work, disconnect the
battery negative (-) terminal in order to prevent a
short in the system.
When disconnecting and reconnecting the battery
cable, turn the ignition switch and lighting swit ...
Hazard warning switch
INSPECTION
1. HAZARD WARNING SIGNAL SWITCH ASSEMBLY
Check that there is resistance between the
terminals at each switch position as shown in the
chart.
Resistance
Inspect illumination operation.
Connect the positive (+) lead from the battery
to the termina ...
