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.
Oxygen (a/f) sensor heater control circuit
Hint:
Although the dtc titles say oxygen sensor, these dtcs relate to the
air-fuel ratio (a/f) sensor.
Sensor 1 refers to the sensor mounted in front of the three-way
catalytic converter (twc) and
located near the engine assembly.
Description
Refer to dtc p2195 (see page es-292 ...
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 no. 1 Engine cover (see page es-410)
Remove air cleaner cap (see pag ...
Fuel tank
Components
Removal
Discharge fuel system pressure (see page
fu-9)
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.
...