Mercury MerCruiser MCM 454 Mag MPI Service Manual page 620

SERVICE MANUAL NUMBER 23
MEFI 2 - 7.4L MPI Symptom Chart (J-1 Circuits) (Continued)
Index
90-861326--1 MARCH 1999
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Circuit
(CKT) (CKT)
Pin Pin
Pin
Number
Function
(#)
Map
J1-9 432
Signal
TP
J1-10 417
Signal
Ignition
J1-11 439
Fused
J1-12 Not Used –
TP and
J1-13 813
IAT
Ground
ECM
J1-14 450
Ground
TP 5V
J1-15 416
Refer-
ence
J1-16 Battery 440
J1-17 Not Used –
Serial
J1-18 461
Data
J1-19 Not Used –
J1-20 Not Used –
J1-21 Not Used –
J1-22 Not Used –
J1-23 Not Used –
IAT Sen-
J1-24 472
sor
J1-25 Not Used –
J1-26 Not Used –
Normal Voltage
Wire Wire
Color Ignition Engine
ON Running
LT 1.46V
4.9V
GRN
(NOTE 3)
DK .62V .62V
BLU
(NOTE 4) (NOTE 4)
PNK B+ B+
– – –
0 0
BLK
(NOTE 5) (NOTE 5)
0 0
BLK
(NOTE 5) (NOTE 5)
GRY 5V 5V
ORN B+ B+
– – –
ORN 5V 5V
– – –
– – –
– – –
– – –
– – –
TAN 5V
(NOTE 2)
– – –
– – –
GENERAL SYSTEM DIAGNOSTICS
Diagnostic
Trouble Tro ble
Possible Possible
Codes
Symptoms
DTC(s)
Poor Perfor-
mance,
Surge, Poor
33
Fuel Econo-
my, Exhaust
Odor
Poor Perfor-
mance And
21 Accelera-
tion, Incor-
rect Idle
None No Start
– –
High Idle,
Rough Idle,
21,23
Poor Perfor-
mance Ex-
haust Odor
None No Start
Lack Of
21
Power, Idle
High
None No Start
– –
No Serial
None
Data
(NOTE 6)
– –
– –
–
– –
– –
Poor Fuel
Economy,
23
Exhaust
Odor
– –
– –
Page 5E-27