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:
Dtc check / clear
Check dtc
Connect the intelligent tester (with can vim) to the
dlc3.
Turn the ignition switch on and turn the intelligent
tester on.
Select the following menu items: diagnosis /
obd/mobd / immobiliser / dtc info /
current codes.
Check dtcs and then write them down.
Hint ...
Diagnosis system
Description
Power door lock control system data can be read in the
data link connector 3 (dlc3) of the vehicle. When the
system seems to be malfunctioning, use the intelligent
tester to check for malfunctions and perform repairs.
Check dlc3
The ecu uses iso 15765-4 for communi ...
Headlight relay
On-vehicle inspection
Remove headlight relay
Remove the headlight relay from the engine room
no. 2 Relay block.
Measure the resistance of the relay.
Standard resistance
If result is not as specified, replace the relay. ...
