Mercury MerCruiser ECM 555 User manual

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Manual Outline
1 - General Information
A - General Information
2 - Troubleshooting
A - Troubleshooting
3 - Wiring Diagrams
A - Wiring Diagrams–ECM with 10-Pin Harness
B - Wiring Diagrams—ECM with 14-Pin Harness
General Information 1
Troubleshooting 2
Wiring Diagrams 3

ECM 555
Diagnostics
Serial Number: OM300000 & Above
©2006, Mercury Marine. All rights reserved. Printed in U.S.A. 90-864573001 DECEMBER 2006
#36 Service Manual
#36 ECM 555 Diagnostics S/N OM300000 & Above
www.mercurymarine.com.au
Private Bag 1420
Dandenong South 3175
Victoria, Australia
www.mercurymarine.com
P.O. Box 1939
Fond du Lac, WI 54936-1939 USA
www.marinepower.com
(Parc Industriel de Petit-Rechain)
B-4822 Verviers/Belgium
90-864573001cvr.qxp 12/13/2006 11:42 AM Page 1

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Notice to Users of This Manual
Throughout this publication, dangers, warnings, cautions, and notices (accompanied by
the International HAZARD Symbol !) are used to alert the mechanic to special
instructions concerning a particular service or operation that may be hazardous if
performed incorrectly or carelessly. These safety alerts follow ANSI standard Z535.6‑2006
for product safety information in product manuals, instructions, and other collateral
materials. Observe them carefully!
These safety alerts alone cannot eliminate the hazards that they signal. Strict compliance
to these special instructions when performing the service, plus common sense operation,
are major accident prevention measures.
! DANGER
Indicates a hazardous situation which, if not avoided, will result in death or serious injury.
! WARNING
Indicates a hazardous situation which, if not avoided, could result in death or serious
injury.
! CAUTION
Indicates a hazardous situation which, if not avoided, could result in minor or moderate
injury.
NOTICE
Indicates a situation which, if not avoided, could result in engine or major component
failure.
IMPORTANT: Identifies information essential to the successful completion of the task.
NOTE: Indicates information that helps in the understanding of a particular step or action.
This manual has been written and published by the Service Department of Mercury Marine
to aid our dealers’ mechanics and company service personnel when servicing the products
described herein. We reserve the right to make changes to this manual without prior
notification.
© 2006, Mercury Marine
Mercury, Mercury Marine, MerCruiser, Mercury MerCruiser, Mercury Racing, Mercury
Precision Parts, Mercury Propellers, Mariner, Quicksilver, #1 On The Water, Alpha, Bravo,
Pro Max, OptiMax, Sport‑Jet, K‑Planes, MerCathode, RideGuide, SmartCraft, Zero Effort,
M with Waves logo, Mercury with Waves logo, and SmartCraft logo are all registered
trademarks of Brunswick Corporation. Mercury Product Protection logo is a registered
service mark of Brunswick Corporation.
It is assumed that these personnel are familiar with marine product servicing procedures.
Furthermore, it is assumed that they have been trained in the recommended service
procedures of Mercury Marine Power Products, including the use of mechanics’ common
hand tools and the special Mercury Marine or recommended tools from other suppliers.
We could not possibly know of and advise the marine trade of all conceivable procedures
and of the possible hazards and/or results of each method. Therefore, anyone who uses
a service procedure and/or tool, which is not recommended by the manufacturer, first must
completely satisfy himself that neither his nor the products safety will be endangered.

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All information, illustrations, and specifications contained in this manual are based on the
latest product information available at the time of publication. As required, revisions to this
manual will be sent to all dealers contracted by us to sell and/or service these products.
Refer to dealer service bulletins, operation maintenance and warranty manuals, and
installation manuals for other pertinent information concerning the products described in
this manual.
Precautions
It should be kept in mind, while working on the product, that the electrical and ignition
systems are capable of violent and damaging short circuits or severe electrical shocks.
When performing any work where electrical terminals could possibly be grounded or
touched by the mechanic, the battery cables should be disconnected at the battery.
Any time the intake or exhaust openings are exposed during service they should be
covered to protect against accidental entrance of foreign material into the cylinders which
could cause extensive internal damage when the engine is started.
During any maintenance procedure, replacement fasteners must have the same
measurements and strength as those removed. Numbers on the heads of the metric bolts
and on the surfaces of metric nuts indicate their strength. American bolts use radial lines
for this purpose, while most American nuts do not have strength markings. Mismatched or
incorrect fasteners can result in damage or malfunction, or possibly personal injury.
Therefore, fasteners removed should be saved for reuse in the same locations whenever
possible. Where the fasteners are not satisfactory for reuse, care should be taken to select
a replacement that matches the original.
Replacement Parts
Use of parts other than the recommended service replacement parts will void the warranty
on those parts that are damaged as a result.
! WARNING
Avoid fire or explosion hazard. Electrical, ignition, and fuel system components on
Mercury Marine products comply with U.S. Coast Guard rules to minimize risk of fire or
explosion. Do not use replacement electrical or fuel system components that do not
comply with these rules. When servicing the electrical and fuel systems, properly install
and tighten all components.
Cleanliness and Care of Product
A Mercury Marine Power Product is a combination of many machined, honed, polished,
and lapped surfaces with tolerances measured in the ten thousands of an inch/mm. When
any product component is serviced, care and cleanliness are important. It should be
understood that proper cleaning and protection of machined surfaces and friction areas is
a part of the repair procedure. This is considered standard shop practice even if not
specifically stated.
Whenever components are removed for service, they should be retained in order. At the
time of installation, they should be installed in the same locations and with the same mating
surfaces as when removed.
Personnel should not work on or under an engine that is suspended. Engines should be
attached to work stands, or lowered to ground as soon as possible.

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