Vehicle Damage Warnings
ELECTRICAL AND ELECTRONICTo avoid possible damage to the electronic components, always follow testing procedures and observe the following precautions:
1. Always ensure the battery is properly connected to the vehicle prior to attempting to start engine.
2. Do not disconnect the battery when the engine is running.
3. Fully release locks prior to disconnecting connections, ensure connectors are fully seated and all insulators and shields are in place when reinstalling.
4. Never connect or disconnect electrical connections with the ignition switch in the "ON" position unless specifically directed to do so in a test procedure.
5. Do not use a self powered test lamp to check continuity.
6. Do not create any arcing to check the continuity of a circuit.
7. When charging the battery, ensure battery cables are removed.
8. To prevent possible Electrostatic Discharge (ESD) damage to the internal components of the computer or to other delicate integrated circuits, DO NOT touch these components without the use of wrist ground straps which have a minimum resistance of 1 Megohm.
9. When replacing electronic components, disconnect the battery ground.
CAUTION: Before removing battery ground, record stored trouble codes. Computer memory will be erased when ground cable is removed.
10. When measuring voltage at the control unit harness connector, disconnect harness connector first, then turn ignition "ON" as necessary.
NOTE: Before replacing the Single Board Engine Controller II (SBEC II) use a DVOM to check the resistance of each computer controlled relay and solenoid coil. See SCHEMATIC DIAGRAMS/ELECTRICAL AND ELECTRONIC DIAGRAMS.
11. To prevent deforming the electronic control unit harness connectors, do not probe terminals directly. Instead, insert a pin from the harness side and perform measurements through pin.
12. Avoid getting water on any of the Fuel or Engine Control System Components.
13. Always use recommended power source in each testing procedure.
14. Never apply full battery voltage or ground to a component unless told to do so in a test procedure.
15. Do not try to disassemble the control unit.
16. Never use an auxiliary starting assist device which has a voltage rating above 12 volts to start engine.
17. In cases of electrical welding (for instance, spot or arc welding), disconnect the climate control, injection, cruise control, computer and radio.
18. In case of temperatures above 176°F (80°C), (example: infra-red spray booth), remove all computers.
19. The battery produces an explosive gas (hydrogen), avoid creating sparks near battery.
20. Not all SCAN TOOLS are compatible with every system. A SCAN TOOL that produces faulty readings should NOT be used, and the problem should be reported to the tool manufacturer. Use of a faulty SCAN TOOL can result in improper diagnosis and unnecessary component replacement. Follow the proper instructions, located in the owners manual, for the specific SCAN TOOL being used.
21. Never touch the control unit connector pins, integrated circuit pins, or soldered components on the control unit circuit board.
22. Use only a digital multi-meter with a minimum 10 meg-ohms internal impedance when testing the control unit or related components unless use of an analog meter is specified by the testing procedure.
ELECTROSTATIC DISCHARGE DAMAGE
Electronic components used in automotive computers are designed to operate at very low voltages (3-5V). These components are very fragile to Electrostatic Discharge (ESD). Voltages as low as 12 volts can damage computer circuits. By comparison, it takes as much as 4,000 volts of ESD for a person to even feel the electric shock, and there is no way of knowing whether the charge on your body is positive or negative.
There are several ways in which a person can become statically charged. The most common methods of charging are by 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. Static charges are gradually equalized by moisture in the air, but are retained much longer when humidity is low.
USE OF PROPER TOOLS AND TESTING PROCEDURES
Use a Digital Multimeter (DVOM) with a minimum 10 Megohms input impedance when testing a computer 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 to avoid damage to low voltage computer circuits and components.
Always follow recommended testing procedures. Never ground or apply voltage to a circuit unless otherwise specified from a given testing procedure. On-board computers provide a regulated constant low voltage source to some circuits, which may require a minimum resistance (impedance) to operate. Directly grounding or applying battery power to these circuits could damage the computer and cause a system failure.
CAUTION: To avoid possible damage to electronic components, observe the following precautions:
1. Discharge any ESD before handling sensitive parts by touching ground or maintaining a ground connection to a bare skin area like the wrist. DO NOT touch these components without the use of wrist ground straps which have a minimum resistance of 1 Megohm.
2. Never touch the computer connector pins, integrated circuit connector pins, or soldered components on the computer circuit board.
3. Fully release connector locks prior to disconnecting from harness; ensure connectors are fully seated, and all insulators and shields are in place when reinstalling.
FUEL SYSTEMS
1. Do not operate the fuel pump without fuel in the lines.
2. Do not depress the accelerator pedal while trying to start the vehicle.
3. Handle all fuel injection related parts with care as they may easily become damaged.
4. Always use new gaskets or O-rings when installing fuel lines or injectors.
5. Lightly lubricate O-rings and flare connections with petroleum jelly. Do not use engine oil, gear lubricant or brake fluid.
6. Relieve the fuel system pressure before servicing the components.
7. After servicing fuel system, check for leaks and correct as needed.
8. DO NOT use Teflon tape or any similar material to seal fuel fittings, unless specifically directed to do so in a repair procedure.
9. DO NOT loosen or turn the fuel injection pump with the engine running unless specifically directed to do so in a repair procedure.
ENGINE AND EXHAUST
1. On vehicles equipped with diesel engines, the following conditions must be observed:
a. Use only "DIESEL 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. Avoid push or pull starting the vehicle.
e. Use caution when working near the exhaust to prevent the possibility of burns.
f. In cold weather, ensure the fuel temperature remains above freezing to prevent the fuel from gelling.
g. Service the engine on regular scheduled maintenance intervals to ensure proper engine performance and lower emission levels.
2. If the vehicle is equipped with glow plugs/air intake heaters, DO NOT attempt to start the vehicle until the "Wait To Start" lamp goes out.
3. Always be conscious of the color of smoke the diesel vehicle emits. A normal diesel engine will emit a small amount of grayish black smoke and will exude a slight diesel fuel smell.
4. Do not ENERGIZE the air intake heater relays more than once every 15 minutes. If the relays are cycled, turning the ignition switch Off and then back ON, wore than once every 15 minutes, the engine could be damaged.