
Propulsion Control Module (PCM)
PCM 112 Controller
56833
All engine models with or without emission control have a 112‑pin propulsion control module (PCM) to manage closed‑loop
engine operation based on oxygen sensor feedback. The battery power requirements of the new PCM requires the use of a
separate PCM power harness for clean power. This new PCM allows fault maintenance that conforms to the onboard
diagnostics ‑ marine (OBD‑M) requirements mandated by California Air Resource Board (CARB) regulations.
The PCM 112 ignition system consists of a battery, PCM 112 controller, main power relay (MPR), fuse, crankshaft position
sensor (CPS), ignition coil harnesses, ignition coils, spark plug wires, and spark plugs.
The PCM 112 controls all ignition system functions, and constantly adjusts dwell and spark timing. It uses engine speed and
position information from the crankshaft to control the sequence, dwell, and timing of the spark. The PCM 112 also monitors
information from various sensor inputs that include the following:
•
The throttle position sensor (TPS)
•
The engine coolant temperature (ECT) sensor
•
The manifold air temperature (MAT) sensor
•
The manifold absolute pressure (MAP) sensor
The ignition coil driver controls the ignition coils. The PCM 112 sends a signal to the ignition coil driver to complete the ground
path for the coil primary winding 12‑volt power source. After the proper dwell time has been reached, the PCM 112 signal is
removed from the driver and the ground path for the coil primary winding is opened, causing the ignition coils to fire.
PCM Removal and Installation
!
WARNING
Performing service or maintenance without first disconnecting the battery can cause product damage, personal injury, or
death due to fire, explosion, electrical shock, or unexpected engine starting. Always disconnect the battery cables from the
battery before maintaining, servicing, installing, or removing engine or drive components.
Electrical Components
90-8M0099748 eng DECEMBER 2015
© 2016 Mercury Marine
Page 4E-5
Summary of Contents for MERCRUISER
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Page 6: ...90 8M0099748 eng DECEMBER 2015 2016 Mercury Marine Page iv...
Page 12: ...General Information Notes Page 1A 6 2016 Mercury Marine 90 8M0099748 eng DECEMBER 2015...
Page 70: ...Maintenance Notes Page 1C 54 2016 Mercury Marine 90 8M0099748 eng DECEMBER 2015...
Page 96: ...Troubleshooting Notes Page 1D 26 2016 Mercury Marine 90 8M0099748 eng DECEMBER 2015...
Page 156: ...Installation Notes Page 2B 52 2016 Mercury Marine 90 8M0099748 eng DECEMBER 2015...
Page 202: ...Engine Disassembly Notes Page 3A 46 2016 Mercury Marine 90 8M0099748 eng DECEMBER 2015...
Page 286: ...Engine Troubleshooting Notes Page 3C 14 2016 Mercury Marine 90 8M0099748 eng DECEMBER 2015...
Page 314: ...Waste Spark System Notes Page 4B 8 2016 Mercury Marine 90 8M0099748 eng DECEMBER 2015...
Page 330: ...Charging System Notes Page 4C 16 2016 Mercury Marine 90 8M0099748 eng DECEMBER 2015...
Page 404: ...MPI ECT Fuel System Notes Page 5A 34 2016 Mercury Marine 90 8M0099748 eng DECEMBER 2015...
Page 424: ...All Models Notes Page 6A 20 2016 Mercury Marine 90 8M0099748 eng DECEMBER 2015...
Page 448: ...Models with Closed Cooling Notes Page 6C 20 2016 Mercury Marine 90 8M0099748 eng DECEMBER 2015...
Page 462: ...Water Flow Diagrams Notes Page 6D 14 2016 Mercury Marine 90 8M0099748 eng DECEMBER 2015...
Page 474: ...Important Information Notes Page 7A 12 2016 Mercury Marine 90 8M0099748 eng DECEMBER 2015...
Page 477: ...Manifolds and Elbows Notes 90 8M0099748 eng DECEMBER 2015 2016 Mercury Marine Page 7B 3...
Page 538: ...Compact Hydraulic Steering Notes Page 8B 12 2016 Mercury Marine 90 8M0099748 eng DECEMBER 2015...
Page 558: ...Notes Color Diagrams Page 10A 2 2016 Mercury Marine 90 8M0099748 eng DECEMBER 2015...
Page 559: ...Notes Color Diagrams 90 8M0099748 eng DECEMBER 2015 2016 Mercury Marine Page 10A 3...
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