PleasureCraft Engine Group 5.0L, Diagnostic Manual

Page: 220 / 337

5 - 78 Diagnosis 5.0/5.7/6.0/8.1L
MEFI 4 - PCM
Diagnostic Procedure (DP) A-7B Electronic Ignition System Diagnosis (6.0/8.1L Only)
ECM Ground
Ignition Feed
To Fuse Block
Term. "A"
From System Relay Term. "87"
Ignition Control E
Spark
Plug
Ignition Coil
(cylinder #6)
Firing Order:
1 - 8 - 7 - 2 - 6 - 5 - 4 - 3
Ignition Control: A - B - C - D - E - F - G - H
Ignition Coils
(cylinders #2 & #4)
Ignition Coils
(cylinders #2,
#4 & #8)
Ignition Coil
(cylinder #8)
Engine
Control
Module
(ECM)
BLK 151
BLK 151
BLK 151
BRN
2129 BRN
2129
BLK 450
BLU/
WHT 2126
BLU/
WHT 2126
PPL 902
PNK 439
PNK 39
C110
S133
S111
S129
S131
S121
S122
J1 J2
M4071P
2-10-04
Ignition Reference
Low IC Signal
Ground
29
19
29
J2
A
D C
C H E
A
B
Hot in Run And Start
INJ/ECM Fuse
20A
Fuse Block
C
D
To S112
(Ground)
To Ignition Coil
Connector (even cyl.)
Term. "H"
To Ignition Coil
Connector (odd cyl.)
Term "E"
To Fuel Pump
Relay Term.
"86"
To Fuel Inj.
Connector
Term. "J"
To Fuel Inj.
Connector
Term. "K"
Diagnostic Aids
Check for the following conditions:
•
Poor connection at ECM. Inspect harness
connectors for backed out terminals, improper
mating, broken locks, improperly formed or
damaged terminals and poor terminal to wire
connection.
•
Corrosion
•
Mis-routed harness
•
Rubbed through wire insulation
•
Broken wire inside the insulation
Test Description
2. This step verifi es the fault is present.
4. This step tests the integrity of the IC circuit and the
ECM output.
5. This step tests for a short to ground on the IC signal
circuit.
Circuit Description
The ignition system on this engine uses an individual ignition
coil/module for each cylinder. The ECM controls the ignition
system operation. The ECM controls each coil using one
of eight Ignition Control (IC) circuits. The ECM commands
the IC circuit low when a spark event is requested. This
causes the IC module to energize the ignition coil to create
a spark at the spark plug. Each ignition coil/module has
the following circuits:
• A power feed
• A ground circuit
• An Ignition Control (IC) circuit
• A reference low circuit
Sequencing and timing are ECM controlled. This DTC
sets when the IC circuit is out of range.