Toyota RAV4 Service Manual: Battery temperature sensor circuit
Description
The battery temperature sensor installed on the battery current sensor detects battery temperature.
A thermistor is integrated into the battery temperature sensor, and the resistance in the battery temperature sensor changes according to the battery temperature.
The resistance of the thermistor in the battery temperature sensor decreases as the battery temperature increases. The resistance increases as the temperature decreases.
The battery temperature sensor is connected to the ecm. The ecm supplies 5 v from the thb terminal to the battery temperature sensor through resistor r.
The battery temperature sensor and resistor r are connected in series. This results in fluctuations in the voltage supplied from the thb terminal when the resistance changes according to the battery temperature.
The ecm determines the battery temperature according to fluctuations in voltage. When the battery temperature is high, the ecm determines to reduce the amount of current supplied from the generator in order to protect the battery.
Wiring diagram
Refer to dtc p1550 (see page es-262)
Inspection procedure
- Inspect battery current sensor
- Disconnect the b29 battery current sensor connector.
- Measure the resistance.
Standard resistance 
- Check harness and connector (battery current sensor - ecm)
- Disconnect the b29 battery current sensor connector.
- Disconnect the b30 ecm connectors.
- Measure the resistance of the wire harness side connectors.
Standard resistance (check for open)
Standard resistance (check for short)
Cold start
Description
The electronic throttle control system (etcs) controls the engine idling
speed. The etcs operates the
throttle actuator to open and close the throttle valve, and adjusts the intake ...
System voltage
Description
The battery supplies electricity to the ecm even when the ignition switch is
in the off position. This
power allows the ecm to store data such as dtc history, freeze frame data and ...
Other materials:
Insufficient coolant temperature for closed loop fuel control
Description
Refer to dtc p0115 (see page es-105).
Monitor description
The resistance of the ect sensor varies in proportion to the actual ect. The
ect supplies a constant
voltage to the sensor and monitors the signal output voltage of the sensor. The
signal voltage output
varies acc ...
Terminals of ecu
Check transponder key amplifier
Disconnect the e5 amplifier connector.
Measure the resistance of the wire harness side
connector.
If the result is not as specified, there may be a
malfunction in the wire harness.
Reconnect the e5 amplifier connector.
Measure the resist ...
Disassembly
Fix differential carrier sub-assembly
Fix the rear differential carrier in place with the
overhaul attachment.
Remove stud bolt
Remove the 4 stud bolts from the transmission
coupling.
Remove differential drain plug
Using a 10 mm socket hexagon wrench, remove ...