PleasureCraft Engine Group 5.0L, Diagnostic Manual

Page: 144 / 337

5 - 2 Diagnosis 5.0/5.7/6.0/8.1L
MEFI 4 - PCM
Diagnosis
The diagnostic procedures and functional checks in this
manual are designed to locate a faulty circuit or component
through logic based on the process of elimination. The
procedures are prepared with the requirement that the
system functioned correctly at the time of assembly and
that there are no multiple failures.
Engine control circuits contain many special design features
not found in standard vehicle wiring. Environmental
protection is used extensively to protect electrical contacts.
Proper splicing methods must be used when necessary.
The proper operation of low amperage input/output circuits
depend upon good continuity between circuit connectors. It
is important before component replacement and/or during
normal troubleshooting procedures that a visual inspection
of any questionable mating connector is performed. Mating
surfaces should be properly formed, clean and likely to
make proper contact. Some typical causes of connector
problems are listed below:
•
Improperly formed contacts and/or connector
housing.
•
Damaged contacts or housing due to improper
engagement.
•
Corrosion, sealer or other contaminants on the contact
mating surfaces.
•
Incomplete mating of the connector halves during
initial assembly or during subsequent troubleshooting
procedures.
•
Tendency for connectors to come apart due to vibration
and/or temperature cycling.
•
Terminals not fully seated in the connector body.
•
Inadequate terminal crimps to the wire.