2. Precautions when connecting devices.
- a) Use the battery as a power source for the stroboscope, tachometer, etc.
- b) Connect the tachometer test lead to the "IG" (-) terminal of the diagnostic connector.
3S-FE, 4A-FE, 4S-FE and 7A-FE | 
3S-GE, 5E-FE |
3. If the engine misfires, take the following precautions.
- a) The battery terminals must be securely connected to the battery terminal posts.
- b) Work carefully with high-voltage wires.
- c) After completing the repair work, make sure that all ignition system wires are correctly and securely connected,
- d) When cleaning the engine compartment, do not allow water to come into contact with the electronic system components.
4. When working with an oxygen sensor;
- c) Do not allow the oxygen sensor to fall or be subjected to impact;
- b) Do not allow water to enter the oxygen sensor.