Vehicle Damage Warnings
ELECTRICAL AND ELECTRONIC SERVICE
ELECTROSTATIC DISCHARGE DAMAGE
Electronic components used in automotive computers are designed to operate at very low voltages (3-5V) and are extremely susceptible to damage caused by static electrical discharge. Voltages as low as 12 volts can damage computer circuits. By comparison, it takes as much as 4,000 volts of static discharge for a person to even feel the "ZAP" and there is no way of knowing whether the charge is positive or negative.
There are several ways a person can become statically charged, the most common of which are friction and induction. Friction between organic materials (such as cotton or leather) and synthetics (such as plastic, vinyl, or glass) will generate static charges as great as 25,000 volts. This can happen by simply sliding across a car seat or by wearing a cotton shirt under a coat made of synthetic materials. Charging by induction occurs when a person standing near a highly charged object (strong magnetic field such as a transformer) momentarily touches ground. Like charges are displaced to ground, leaving the person highly charged with opposite polarity. Static charges are gradually equalized by moisture in the air, but are retained much longer when humidity is low. Touch ground to discharge static electrical charges before handling electronic parts and maintain a bare skin ground connection (such as on the wrist) when servicing sensitive components.
USE OF PROPER TOOLS AND TESTING PROCEDURES
Use a digital volt/ohm meter (DVOM) with a minimum 10 mega-ohms internal impedance when testing an ECU or related components unless use of an analog meter is specified by a testing procedure. Analog meters have low internal impedance and cause circuit "loading" in low voltage circuits, resulting in inaccurate measurements and possible damage to components. Use of a DVOM is necessary to obtain accurate measurements and avoid damaging low voltage ECU circuits and components.
Always follow recommended testing procedures. Never ground or apply voltage to a circuit unless specified by a testing procedure. The ECU provides a regulated constant low voltage to circuits which may require a minimum resistance (impedance) to operate. Directly grounding or applying battery power to these circuits could damage the ECU and cause a system failure.
NOTICE: To avoid possible damage to electronic components, observe the following precautions:
1. Touch ground to discharge static electrical charges before handling electronic parts and maintain a bare skin ground connection (such as on the wrist) when servicing sensitive components.
2. Never touch ECU connector pins, integrated circuit connector pins or soldered components on the ECU circuit board.
3. Ensure that the battery is properly connected before attempting to start engine.
4. Do not disconnect the battery when the engine is running.
5. Fully release harness connector locks prior to parting connectors. Ensure connectors are fully seated and all insulators and shields are in place when reinstalling.
6. Never connect or disconnect electrical connections with the ignition switch in the "ON" position unless specifically directed to do so in a test procedure.
7. In order to disable the ignition system, unplug the primary connections only. NEVER disconnect the secondary leads to disable the ignition system.
8. Do not use a self powered test lamp to check continuity.
9. Do not create any arcing to check the continuity of a circuit.
10. When charging a battery, disconnect cables.
11. When replacing electronic components, disconnect the battery ground.
NOTE: Before removing battery ground, access trouble codes. ECU memory will be erased if ground cable is removed.
12. When measuring voltage at the control unit harness connector, disconnect harness connector first. Then turn ignition "ON" as necessary.
13. To prevent deforming control unit harness connectors, do not probe terminals directly. Insert a pin from the harness side and perform measurements through pin.
14. Avoid getting water on fuel system and electronic engine control components.
15. Fuel and engine control system wiring should be at least 4 inches away from high tension cables.
16. Never pierce ignition leads or insulator boots to connect timing lights or analyzers. Use proper adapters.
17. When removing a spark plug wire, twist the boot one quarter turn and pull on the boot only. Never pull on the lead itself.
18. Always use 12-volt batteries as a power source.
19. Never apply battery power to a component unless directed to do so in a test procedure.
20. Do not try to disassemble the control unit.
21. Never use a booster/starter which has a voltage rating above 12 volts to start engine.
22. Before performing electrical welding, disconnect the climate control, injection, cruise control, ECU and radio.
23. When temperatures may exceed 176°F (80°C), such as in an infra-red spray booth, remove all ECUs.
24. Batteries contain acid and produce explosive hydrogen gas. Avoid creating sparks near battery.
FUEL SYSTEMS
1. Do not operate the fuel pump without fuel.
2. On fuel injected models, do not depress the accelerator pedal while trying to start the car.
3. Handle all fuel injection parts with care to avoid damage and contamination.
4. Always use new gaskets or O-rings when installing fuel lines or injectors.
5. Lightly lubricate O-rings and flare connections with gasoline. Do not use engine oil, gear lubricant or brake fluid.
6. After fuel system service, check for leaks and make any necessary corrections before driving vehicle.
ENGINE AND EXHAUST
1. On vehicles equipped with catalytic converters, the following conditions must be observed:
a. Use only "UNLEADED FUEL".
b. Avoid running out of fuel.
c. In case of poor engine operation (misfiring), avoid driving the vehicle and correct the problem as soon as possible.
d. Do not disconnect any spark plug wires with the engine running.
e. Avoid push starting the vehicle.
f. If running on a dynamometer, make sure the catalytic converter is well ventilated.
g. Use caution when working near the catalytic converter to reduce the possibility of burn injuries.
2. Do not use silicone based products on an oxygen sensor equipped vehicle. Sensor damage may occur.
3. When performing a compression test, remove the fuel pump relay fuse and disconnect ignition system power.