Toyota RAV4 Service Manual: Room temperature sensor circuit
Description
The room temperature sensor is installed in the instrument panel to detect the room temperature and control the heater and air conditioner auto mode. The resistance of the room temperature sensor changes in accordance with the room temperature. 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 room temperature sensor and reads voltage changes as changes in the resistance of the room temperature sensor.
Wiring diagram
Inspection procedure
- Read value of intelligent tester (room 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 cooler thermistor (room temperature sensor)
- Remove the room temperature sensor.
- Measure the resistance of the sensor.
Standard resistance 
Notice:
- Touching the sensor even slightly 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 ambient temperature.
Hint:
As the temperature increases, the resistance decreases (see the graph).
- Check wire harness (room temperature sensor - air conditioning amplifier)
- Disconnect the e21 sensor connector.
- Disconnect the e37 amplifier connector.
- Measure the resistance of the wire harness side connectors.
Standard resistance 
Replace air conditioning amplifier assembly
Diagnostic trouble code chart (2006/01- )
Hint:
When the air conditioning system functions properly, dtc
b1400/00 is output.
Hint:
*1: Dtc b1422/22 (compressor lock sensor circuit) is
indicated only for a currently occurring malf ...
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 ...
Other materials:
Rear window and outside rear view mirror defoggers
These features are used to defog the rear window, and to
remove raindrops, dew and frost from the outside rear view mirrors
(if equipped).
Vehicles with a manual air conditioning system
On/off
The defoggers will automatically
turn off after approximately 15 minutes.
Vehicles with an au ...
Cleaning and protecting
the vehicle interior
The following procedures will help protect your vehicle’s interior
and keep it in top condition:
Protecting the vehicle interior
Remove dirt and dust using a vacuum cleaner. Wipe dirty surfaces
with a cloth dampened with lukewarm water.
Cleaning the leather areas
Remove dirt and dust usin ...
Selecting the audio
source
Switching between audio sources such as radio and cd are
explained in this section.
Changing audio source
Press the “audio” button to display the audio source selection
screen.
If the audio source selection screen is not displayed, press the “audio”
button again.
Select the d ...
