A large number of ecu controlled systems are used in the rav4. In general, ecu controlled systems are considered to be very intricate, requiring a high level of technical knowledge to troubleshoot. However, most problem checking procedures only involve inspecting the ecu controlled system's circuits one by one. An adequate understanding of the system and a basic knowledge of electricity is enough to perform effective troubleshooting, accurate diagnoses and necessary repairs.
For using intelligent tester

Connect the cable of the intelligent tester to the dlc3, turn the ignition switch on and attempt to use the tester. If the display indicates that a communication error has occurred, there is a problem either with the vehicle or with the tester.
* If communication is normal when the tester is connected to another vehicle, inspect the dlc3 of the original vehicle.
* If communication is still not possible when the tester is connected to another vehicle, the problem may be in the tester itself. Consult the service department listed in the tester's instruction manual.
Removal
Disconnect cable from negative battery
terminal
Caution:
Wait at least 90 seconds after disconnecting the
cable from the negative (-) battery terminal to
prevent airbag and seat belt pretensioner activation.
Remove fan and generator v belt
Remove the belt (see page em-6).
...
Before refueling the vehicle
Close all the doors and windows, and turn the engine switch to the
“lock” position (vehicles without a smart key system) or off (vehicles
with a smart key system).
Confirm the type of fuel.
Fuel types
Unleaded gasoline (octane rating 87 [research octane number 91] or
higher)
Cauti ...
Inspection
Inspect engine coolant temperature sensor
Measure the resistance of the sensor.
Standard resistance
Notice:
If checking the sensor in water, be careful not to
allow water to contact the terminals. After
checking, wipe the water off the sensor.
If the result is not as specified, ...