Mercury MerCruiser MCM 454 Mag MPI Service Manual page 597

GENERAL SYSTEM DIAGNOSTICS
J-2
J-2 Output Connector (Rear)
IMPORTANT: The following conditions must be met before testing.
1. Engine at operating temperature.
2. Ignition on or engine running.
3. Scan tool not connected.
THESE NOTES APPLY TO FOLLOWING ECM CONNECTOR AND SYMPTOM CHARTS
The "B+" Symbol indicates a system voltage (battery).
NOTE 1: Battery voltage for first two seconds, then 0 volts.
NOTE 2: Varies with temperature.
NOTE 3: Varies with manifold vacuum.
NOTE 4: Varies with throttle movement.
NOTE 5: Less than .5 volt (500 mV).
Index
Page 5E-4
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a
a - Shaded Area Denotes Pin Connector Location
SERVICE MANUAL NUMBER 23
90-861326--1 MARCH 1999