Toyota RAV4 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:
Freeze frame data
Description
Freeze frame data records the engine conditions (fuel
system, calculated load, engine coolant temperature,
fuel trim, engine speed, vehicle speed, etc.) When a
malfunction is detected. When troubleshooting, it can
help determine if the vehicle was running or stopped, the
engin ...
Disassembly
Remove idler pulley (see page em-23)
Remove oil dipstick
Remove oil dipstick guide (see page em-57)
Remove manifold stay (see page em-57)
Remove no. 2 Manifold stay (see page em-58)
Remove no. 1 Exhaust manifold heat
insulator (see page em-58)
Remove exhaust manifold converter subas ...
Throttle actuator control motor circuit
Description
The throttle actuator is operated by the ecm and opens and closes the
throttle valve using gears.
The opening angle of the throttle valve is detected by the throttle position (tp)
sensor, which is mounted
on the throttle body. The tp sensor provides feedback to the ecm. This ...