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:
Drl relay circuit
Description
The main body ecu controls the daytime running light no. 2 Relay (marking:
drl no.2).
Wiring diagram
Inspection procedure
Inspect daytime running light relay (marking: drl no. 2, Drl no. 3,
Drl no. 4)
Remove the no. 2 Relay, no. 3 Relay and no. 4 Relay from
th ...
Daytime running light relay
On-vehicle inspection
Inspect day time running light relay
Remove the no. 2 Relay, no. 3 Relay and no. 4 Relay
from the engine room no. 2 Relay block.
Measure the resistance of the relays.
Standard resistance:
No. 2, No. 4
No. 3
If the result is not as specified, replace th ...
Eps warning light circuit
Description
If the power steering ecu detects a malfunction, the p/s warning light comes
on. At this time, the power
steering ecu stores a dtc in its memory.
Wiring diagram
Inspection procedure
Check for dtc
Using the intelligent tester (with can vim), check for
dtcs and confir ...