Toyota RAV4 (XA40) 2013-2018 Service Manual: 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 combination meter and detects fluctuations in the ambient temperature. This data is used for controlling the room temperature.
The sensor sends a signal to the air conditioning amplifier via the combination meter. The resistance of the ambient temperature sensor changes in accordance with the ambient 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 ambient temperature sensor and reads voltage changes as changes in the resistance of the ambient temperature sensor. The combination meter sends the read signal to the air conditioning amplifier via can communication.
Wiring diagram
Inspection procedure
- Read value of intelligent tester (ambi temp sens)
- 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 ambient temperature sensor
- Remove the ambient 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 (ambient temperature sensor - combination meter)
- Disconnect the a17 sensor connector.
- Disconnect the e19 meter connector.
- Measure the resistance of the wire harness side connectors.
Standard resistance 
Replace combination meter
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 malfunct ...
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 ...
Other materials:
Passenger airbag on / off indicator circuit malfunction
Description
The passenger airbag on / off indicator circuit consists of the center airbag
sensor and the heater
control panel*1 or *2.
This circuit indicates the operation condition of the front passenger airbag,
the front passenger side airbag
and passenger side seat belt pretensioner ...
Correct use of the seat
belts
Extend the shoulder belt so
that it comes fully over the
shoulder, but does not come
into contact with the neck or
slide off the shoulder.
Position the lap belt as low as
possible over the hips.
Adjust the position of the
seatback.
Sit up straight and well back
in the seat.
Do not twis ...
Mass or volume air flow circuit
Description
The mass air flow (maf) meter is a sensor that measures the amount of air
flowing through the throttle
valve.
The ecm uses this information to determine the fuel injection time and to
provide the appropriate air-fuel
ratio.
Inside the maf meter, there is a heated platinu ...
