Mercury MerCruiser MCM 454 Mag MPI Service Manual page 672

SERVICE MANUAL NUMBER 23
Chart A-5 (2 of 3): Fuel System Electrical Test
Step
Index
90-861326--1 MARCH 1999
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Action
Was The "On-Board Diagnostic"
1 (OBD) System
Performed?
1. Ignition "OFF".
2. Remove fuel pump relay.
3. Ignition "ON".
4. Using test light connected to
2 ground, probe fuel pump
relay harness connector ter-
minal "30."
Does Test Light Illuminate
Brightly?
1. Ignition "OFF".
2. Using a fused jumper wire,
connect terminals "30" and
3
"87" of the fuel pump relay
connector together.
3. Ignition "ON."
Does Fuel Pump Run?
1. Ignition "OFF".
2. Disconnect fused
wire.
3. Using a test light connected
4 to battery positive (B+), probe
terminal "86" of the fuel pump
relay connector.
Does The Test Light Illuminate
Brightly?
1. Using a test fight connected
to ground, probe terminal
"85" of the fuel pump relay
connector.
5
2. Ignition "ON".
Does Test Light Illuminate
Brightly For 2 Seconds And
Then Go Off?
Locate and repair faulty ECM
connection at "J2-9" or repair
6
open in CKT 465.
Was A Problem Found?
Check fuel pump relay fuse.
7
Is Fuse Ok?
Replace fuel pump relay and
retest.
8
Is Fuel Pressure
Specified Values?
Value(s)
Check –
Go to Step 2
–
Go to Step 3
–
Go to Step 4
jumper
–
Go to Step 5
–
Go to Step 6
Go to OBD
–
Go to Step
–
34-38 psi
Go to OBD
(234-262
Within
kPa)
GENERAL SYSTEM DIAGNOSTICS
Yes No
Go to OBD
System Check
Go to Step 7
Go to Step 12
Go to Step 14
Go to Step 6
System
Go to Step 15
Check
Go to Step 11
10
System
Go to Step 9
Check
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