Mitsubishi Galant (2004+). Manual - part 1069

INSPECTION PROCEDURE USING AN OSCILLOSCOPE

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-1093

Alternate method (Measure at the PCM)

1. Disconnect the all PCM connectors, and connect check har-

ness special tool (MB991923) between the separated con-
nectors.

2. Connect the oscilloscope probe to each check harness con-

nector terminal to analyze each cylinder:

• Terminal No. 151 for the number 1 cylinder.

• Terminal No. 143 for the number 2 cylinder.

• Terminal No. 150 for the number 3 cylinder.

• Terminal No. 148 for the number 4 cylinder.

AK202954

127 126 125 124 123 122 121

133 132 131 130 129 128

140 139 138 137 136 135 134

146 145 144 143 142 141

153 152 151 150 149 148 147

AB

POWER PLANT ECU 
CHECK HARNESS CONNECTOR

MB991923

PCM

127 126 125 124 123 122 121

133 132 131 130 129 128

140 139 138 137 136 135 134

146 145 144 143 142 141

153 152 151 150 149 148 147

AK303941AB

OSCILLOSCOPE

POWER PLANT ECU
CHECK HARNESS
CONNECTOR

INSPECTION PROCEDURE USING AN OSCILLOSCOPE

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-1094

Standard Wave Pattern

Observation condition

Function

Special pattern

Pattern height

Low

Pattern selector

Display

Engine r/min

Idle speed

AK304080

(VOLT)

TDC

0

10

Standard wave pattern

2 ENGINE REVOLUTIONS (1 CAMSHAFT REVOLUTION)

AB

0

10

OFF

ON

(TIME)

IGNITION
TIMING

DWELL
SECTION

CRANKSHAFT
POSITION
SENSOR OUTPUT
WAVE PATTERN

IGNITION POWER
TRANSISTOR
CONTROL SIGNAL
WAVE PATTERN

INSPECTION PROCEDURE USING AN OSCILLOSCOPE

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-1095

Wave Pattern Observation Points
Point: The power transistor control signal (ignition timing) is 

advanced when the engine speed is increased.

.

Examples of Abnormal Wave Patterns
Example 1 (Wave pattern during engine cranking)

• Cause of problem

Open-circuit in ignition primary circuit

• Wave pattern characteristics

Voltage value is too low.

CONDITION OF WAVE 
PATTERN BUILD-UP 
SECTION AND MAXIMUM 
VOLTAGE

PROBABLE CAUSE

Voltage value is too low

Open-circuit in ignition primary 
circuit

AK203246

NORMAL WAVE
PATTERN

AC

SPECIAL TOOLS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-1096

SPECIAL TOOLS

M1131000600643

TOOL

TOOL NUMBER AND 
NAME

SUPERSESSION

APPLICATION

MB991958
A: MB991824
B: MB991827
C: MB991910
D: MB991911
E: MB991914
F: MB991825
G: MB991826
MUT-III sub assembly
A: Vehicle 
Communication Interface 
(V.C.I.)
B: MUT-III USB Cable
C: MUT-III Main Harness 
A (Vehicles with CAN 
communication system)
D: MUT-III Main Harness 
B (Vehicles without CAN 
communication system)
E: MUT-III Main Harness 
C (for Daimler Chrysler 
models only)
F: MUT-III Adapter 
Harness
G: MUT-III Trigger 
Harness

MB991824-KIT
NOTE: G: MB991826 
MUT-III Trigger Harness 
is not necessary when 
pushing V.C.I. ENTER 
key.

• Reading diagnostic 

trouble code

• MFl system inspection

• Measurement of fuel 

pressure

CAUTION

For vehicles with CAN 
communication, use 
MUT-III main harness A 
to send simulated 
vehicle speed. If you 
connect MUT-III main 
harness B instead, the 
CAN communication 
does not function 
correctly.

MB991923
Power plant ECU check 
harness

MD998478-01

• Inspection using an 

oscilloscope

• Inspection of the 

powertrain control 
module (PCM) 
terminal voltage check

MB991910

MB991826

MB991958

MB991911

MB991914

MB991824

MB991827

MB991825

DO NOT USE

A

B

C

D

E

F

G

DO NOT USE

MB991923