MerCruiser Thunderbolt V Ignition
Page 52
Thunderbolt V
is section describes a procedure which allows marine service technicians to
obtain engine operating hour information from a underbolt V module. is
information is not useful for diagnosing ignition performance related problems.
If you are trying to diagnose ignition system problems please refer to an appro-
priate MerCruiser factory service manual for ignition system diagnostic proce-
dures.
e MerCruiser underbolt V ignition module is a microprocessor based
electronic ignition controller. e module incorporates a variety of performance
related features and is designed to provide optimum spark advance throughout
the engine’s operating range. ree versions of the underbolt V module are
currently in existence. Two of the three versions are capable of providing histori-
cal engine operating information to the TechMate Pro scan tool.
e 1st generation underbolt V module was originally introduced during
the 1994 model year. Although this generation module provided precise spark
control for the engine, it was superseded in 1996 and again in 1998 by second
and third generation models which contained data logging capabilities. ese
newer underbolt V modules are equipped with the ability to record engine
operating hour information throughout the life of the engine. e 3rd generation
underbolt V module, introduced in 1998, has a redesigned outer case and im-
proved diagnostic terminal connections. MerCruiser has eliminated the module’s
recessed diagnostic terminal connections. All connections to the module are now
integrated into two weather-proof electrical connectors at the module’s base.
Figure 27
1st & 2nd Generation
Thunderbolt V Module
Figure 28
3rd Generation
Thunderbolt V Module
To Next Page
Loading...