Unless instructed in the diagnostic procedure, do not use a test lamp. When a probe connector is required in a diagnostic procedure, use connector test adapter kit (5-8840-2835-0).
When performing an inspection with the engine running in a closed location such as a garage, make sure to adequately ventilate the area in order to ensure the exhaust gas is not breathed in. Take sufficient care as exhaust gas is highly poisonous, and inhaling it can lead to fainting or death.
If a vehicle inspection is performed using a scan tool, firmly engage the parking brake, and stabilize the vehicle using chock blocks.
Aftermarket electronic equipment refers to commercially available electronic equipment installed to the vehicle after it has been shipped from the factory. Be careful, as such accessories are not taken into particular consideration at the vehicle design stage.
Aftermarket electronic equipment may cause malfunctions in the electronic control system, even if the equipment is properly installed. This includes devices not connected to the electrical system of the vehicle, such as mobile phones and radios. Therefore when diagnosing electronic system problems, first confirm whether such aftermarket electronic equipment is installed, and remove it from the vehicle. If the problem has not been resolved after removing the equipment, perform the diagnosis using the regular procedure.
Caution
Because the electronic components used in the electronic control system are designed to operate at extremely low voltages, they can easily be damaged by static electricity, and some types of electronic components can be damaged by a static electricity of 100 V or less, which cannot be felt by humans. (A voltage of 4,000 V is required for a person to be able to detect a static electricity.)
There are various ways a person can build up an electrostatic charge. The most common way to build up an electrostatic charge is through friction or induction. An example of when a person builds an electrostatic charge by friction is when they slide across the seat of the vehicle. A person wearing insulated shoes can build an electrostatic charge by induction if they momentarily touch the ground while standing near a highly charged object. A charge of the same polarity flows out, and with a highly opposing polarity, that person becomes charged. Because static electricity can be damaging, be careful when handling or testing electronic components.
Caution
The control unit is designed to withstand the regular current load associated with vehicle operation. Take care to prevent the circuit from overloading. When inspecting for an open circuit and short circuit, do not ground or apply voltage to the control unit circuit unless instructed to do so. When performing these circuit inspections, make sure to use a DMM (5-8840-0285-3) with a large input impedance. Even when it is clear that there is a failure in the control unit, make sure to verify that there are no abnormal conditions outside of the control unit before replacing it. Failure to do so, for example in cases where the control unit is damaged due to a short circuit in the output circuit, may lead to the new control unit also being damaged.