MerCruiser PCM-555 EFI
Page 39
Fuel Pump Relay Output Test
This test will cause the PCM to energize the fuel pump relay thereby activating
the engine’s electric fuel pump. Upon executing this test the technician should
listen for fuel pump and relay mechanical activity. The relay will be activated for
a period of one second.
• This test should be performed with Key-On and Engine Off.
1) Review the advisory message stated above and be sure the engine is not run-
ning when attempting to perform this test.
2) After selecting the “Fuel Pump Relay“ test from the PCM Output Test menu
the scanner will prompt you to begin the test. To initiate the test press the
TEST key. The fuel pump relay will be activated for approximately one
second.
3) You may press the TEST key again to repeat the test or press the NO key to
return to the Output Test menu.
Ignition Coil Output Test
The Ignition Coil output test allows individual coils and their associated spark
outputs to be fired to verify their operation. This test requires that a spark gap
tester be used to verify proper ignition coil operation. The ignition coil under test
will be fired at a rate equivalent to 1600 rpm. This test helps a technician verify
that a particular ignition coil is receiving a command signal from the PCM and
that the coil’s high voltage output is sufficient to generate a spark discharge.
• WARNING: Use of spark gap tester is required for this test. Do not
perform this test with the ignition wires attached to the engine’s spark
plugs while they are installed in the cylinders.
•
Engine backfire and external flame can occur. As a safety precaution,
purge fuel vapors from the engine before proceeding.
• An approved spark gap tester must be attached to the spark output
under test. See the spark gap tester’s instructions for proper installa-
tion, adjustment and use.
• IMPORTANT: Before performing this test the engine’s electric fuel
pump should be disabled. Disabling of the fuel pump may be accom-
plished by removing the fuel pump fuse or disconnecting the pump’s
electrical connector.
• This test should be performed with Key-On and Engine Off.
1) Review the warnings stated above and be sure the engine is not running when
attempting to perform this test.
2) After selecting the “Ignition Coil“ function from the PCM Output Test menu
Summary of Contents for TechMate Pro
Page 2: ... ...
