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
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Description
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t ...
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Description
The no. 1 Cooler thermistor (evaporator temperature sensor) is installed on
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Description
The occupant classification system detects the front passenger seat condition
and then indicates whether
the front passenger airbag is activated or not through the passenger airbag on /
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Air conditioning control assembly (for manual air conditioning system)
Components
Removal
Disconnect cable from negative battery
terminal
Notice:
Wait at least 90 seconds after disconnecting the
cable from the negative (-) battery terminal to
prevent airbag and seat belt pretensioner activation.
Remove no. 2 Instrument cluster finish
panel center ...
Vc output circuit
Description
The ecm constantly generates 5 v power from the battery voltages supplied to
the +b (batt) terminal to
operate the microprocessor. The ecm also provides this power to the sensors
through the vc output
circuit.
When the vc circuit is short-circuited, the microprocessor in the ...
