CAUTION
Whenever working on or around any computer based microprocessor control system,
always observe these general precautions to reduce the possibility of personal
injury or damage to electronic components.
- Never install or remove battery cables with the key ON or
the engine running.
- Jumper cables should be connected with the key OFF to avoid
power surges that can damage electronic control units.
- Engines equipped with computer controlled systems should avoid both giving
and getting jump starts due to the possibility of serious damage to components
from arcing in the engine compartment when connections are made with the ignition ON.
- Always remove the battery cables before charging the battery.
- Never use a high output charger on an installed battery or attempt to use
any type of "hot shot'' (24 volt) starting aid.
- Exercise care when inserting test probes into connectors to insure good
connections without damaging the connector or spreading the pins. Always probe
connectors from the rear (wire) side, NOT the pin side, to avoid accidental
shorting of terminals during test procedures.
- Never remove or attach wiring harness connectors with the ignition switch ON,
especially to an electronic control unit.
- Do not drop any components during service procedures and never apply 12
volts directly to any component (like a solenoid or relay) unless instructed
specifically to do so. Some component electrical windings are designed to
safely handle only 4 or 5 volts and can be destroyed in seconds if 12 volts
are applied directly to the connector.
- Remove the electronic control unit (module) if the vehicle is to be placed
in an environment where temperatures exceed approximately 176°F (80°C),
such as a paint spray booth or when arc or gas welding near the control unit
location in the truck.
