Mercury MerCruiser MCM 7.4L MPI User Manual

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

Mercury MerCruiser MCM 7.4L MPI Specifications

General

Brand	Mercury
Model	MerCruiser MCM 7.4L MPI
Category	Engine
Language	English