Toyota RAV4 (XA40) 2013-2018 Service Manual: Evaporator temperature sensor circuit
Description
The no. 1 Cooler thermistor (evaporator temperature sensor) is installed on the evaporator in the air conditioning unit to detect the temperature of the cooled air that has passed through the evaporator and to control the air conditioner. It sends signals to the air conditioning amplifier. The signals change in accordance with the resistance of the no. 1 Cooler thermistor (evaporator temperature sensor). As the temperature decreases, the resistance increases. As the temperature increases, the resistance decreases. The air conditioning amplifier applies a voltage (5 v) to the no. 1 Cooler thermistor (evaporator temperature sensor) and reads voltage changes as changes in the resistance of the no. 1 Cooler thermistor (evaporator temperature sensor). This sensor is used for frost prevention.
Wiring diagram
Inspection procedure
- Read value of intelligent tester (evap fin temp)
- Connect the intelligent tester (with can vim) to the dlc3.
- Turn the ignition switch on and turn the intelligent tester main switch on.
- Select the item below in the data list, and read the value displayed on the intelligent tester.
Ok: the display is as specified in the normal condition column.
- Inspect no. 1 Cooler thermistor (evaporator temperature sensor)
- Remove the no. 1 Cooler thermistor.
- Measure the resistance of the thermistor.
Standard resistance 
Notice:
- Touching the thermistor even slightly may change the resistance value. Be sure to hold the connector of the thermistor.
- When measuring, the thermistor temperature must be the same as the ambient temperature.
Hint:
As the temperature increases, the resistance decreases (see the graph).
Replace air conditioning harness assembly
Ambient temperature sensor circuit
Description
The ambient temperature sensor is installed in the front part of the
condenser to detect the ambient
temperature and control the air conditioner. The sensor is connected to the
c ...
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 conditioning auto mode. The output voltage from the solar
se ...
Other materials:
How to proceed with troubleshooting
Hint:
*: Use the intelligent tester.
Hint:
If the display indicates a communication fault in the tester,
inspect the dlc3.
Hint:
Record or print dtcs and freeze frame data, if necessary.
Hint:
If the engine does not start, first perform the "check dtc"
procedures a ...
Fuel Economy
Current fuel economy
Displays the driving range with
remaining fuel.
Average fuel economy
Displays the average fuel economy
since the function was reset or the average fuel economy after starting.* 1,
2, 3
The average fuel economy selected
by "Fuel Economy" on the
screen is displayed.
*1 ...
Basic inspection
When measuring resistance of
electronic parts
Unless otherwise stated, all resistance
measurements should be made at an ambient
temperature of 20°c (68°f). Resistance
measurements may be inaccurate if measured
at high temperatures, i.E. Immediately after the
vehicle has been r ...
