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 pumping current circuit
Description
Refer to dtc p2195 (see page es-292).
Monitor description
The air-fuel ratio (a/f) sensor varies its output voltage in proportion to
the air-fuel ratio. If the a/f sensor
impedance (alternating current resistance) or output voltage deviates greatly
from the standard range ...
Trailer towing
Your vehicle is designed
primarily as a passenger-and-
load-carrying vehicle.
Towing a trailer can have an
adverse impact on handling,
performance, braking, durability,
and fuel consumption.
For your safety and the
safety of others, you must
not overload your vehicle or
trailer. You must also
ensu ...
Headlight relay circuit
Description
When the light control switch, located on the headlight dimmer switch, is
turned to the head position, the
head relay illuminates the headlights.
Wiring diagram
Inspection procedure
Perform active test by intelligent tester (headlight)
Connect the intelligent tester ( ...