Mercury 225 EFI, Service Manual

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IGNITION
90-884294 OCTOBER 2001 Page 2A-17
Electronic Control Module (ECM)
The ECM requires 8 VDC minimum to operate. If the ECM should fail, the engine will stop
running.
The inputs to the ECM can be monitored and tested by the Digital Diagnostic Terminal
91-823686A2 using adaptor harness 84-822560A5.
The ECM performs the following functions:
•
Calculates the precise fuel and ignition timing requirements based on engine speed,
throttle position, manifold pressure and coolant temperature.
•
Controls fuel injectors for each cylinder and ignition for each cylinder.
•
Controls all alarm horn functions.
•
Supplies tachometer signal to gauge.
•
Controls RPM limit function.
•
Contains detonation control circuitry (200 Work Model only)
•
Records engine running information.
a
59026
a - Electronic Control Module (ECM)