Mitsubishi Outlander GS45X. Manual - part 985

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L ENGINE>

13B-873

Measurement Method

1. Disconnect the EGR valve connector, and connect the test 

harness special tool (MB991658) between the separated 
connector (All terminals should be connected).

2. Connect the oscilloscope probe to the EGR valve connector 

terminal No. 1, terminal No. 3, terminal No. 4, terminal No. 6 
respectively.

.

Alternate method 

1. Disconnect all ECM connectors. Connect the check harness 

special tool (MB992110 between the separated connectors.

2. Connect the oscilloscope probe to check harness terminal 

No. 31, No. 32, No. 47 and No. 48.

Standard Wave Pattern

AK700422

1

2 3

4

5 6

AB

EGR valve
connector

Oscilloscope

MB991658

Observation condition

Function

Special pattern

Pattern height

High

Pattern selector

Display

Engine condition

Revving

16 15 14 13 12 11 10 9 8 7 6 5 4 3

2

1

32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17

48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33

64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49

AK700327AB

Power plant ECU
check harness connector

MB992110

AK700423

16 15 14 13 12 11 10 9 8 7 6 5 4 3

2

1

32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17

48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33

64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49

AB

Oscilloscope

Power plant ECU
check harness
connector

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L ENGINE>

13B-874

Wave Pattern Observation Points

1. Check that the standard wave pattern appears when the 

EGR valve is operating.

Point A: Presence or absence of induced electromotive force 

from the motor turning. (Refer to abnormal wave pattern.)

Point B: Height of coil back electromotive force

.

CONTRAST WITH 
STANDARD WAVE 
PATTERN

PROBABLE CAUSE

Induced electromotive force 
does not appear or is 
extremely small

Malfunction of motor

CONTRAST WITH 
STANDARD WAVE 
PATTERN

PROBABLE CAUSE

Coil reverse electromotive 
force does not appear or is 
extremely small

Short in the coil

AK700333AB

(V)

30

20

10

0

EGR valve
(stepper moter)
control signal
wave pattern

Point B coil reverse
electromotive force
(approximately 3 ×10V) Point an induced

electromotive force
from the moter turning

Time

Standard wave pattern

The wave pattern
appears for an
instant, but soon
disappears.

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L ENGINE>

13B-875

Examples of Abnormal Wave Patterns

Example 1
Cause of problem

• Malfunction of motor. (Motor is not operating.)

Wave pattern characteristics

• Induced electromotive force from the motor turning does 

not appear.

Example 2
Cause of problem

• Open circuit in the line between the EGR valve and the 

ECM.

Wave pattern characteristics

• Current is not supplied to the motor coil on the open cir-

cuit side. (Voltage does not drop to 0 volt.) Furthermore, 
the induced electromotive force wave pattern at the nor-
mal side is slightly different from the normal wave pat-
tern.

IGNITION COIL AND IGNITION POWER 
TRANSISTOR

Required Special Tools:

• MB991658: Test Harness

• MB992110: Power Plant ECU Check Harness

.

Measurement Method

Measure at the right bank (number 1, 3, 5 cylinders)

1. Disconnect the intermediate connector B-21, and connect 

the test harness special tool (MB991658) between the sep-
arated connector.

2. Connect the oscilloscope probe to each intermediate con-

nector B-21 terminal to analyze each cylinder:

• Terminal No. 2 for the number 1 cylinder.

• Terminal No. 3 for the number 3 cylinder.

• Terminal No. 4 for the number 5 cylinder.

Measure at the left bank (number 2, 4, 6 cylinders)

1. Disconnect the ignition coil connector, and connect test har-

ness special tool (MB991658) between the separated con-
nector. (All terminals should be connected.)

2. Connect the oscilloscope probe to ignition coil connector 

terminal No. 2.

.

AK700119 AB

AK700120

Open
circuit
side

Normal
side

AB

1

2 3

6

7 8

4 5

9 10

AK700328AB

Oscilloscope

MB991658

B-21 Intermediate
connector

AK700330

2 3

1

AB

Ignition coil
connector

Oscilloscope

MB991658

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L ENGINE>

13B-876

Alternate method 

1. Disconnect all ECM connectors. Connect the check har-

ness special tool (MB992110) between the separated con-
nectors.

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

nector terminal to analyze each cylinder:

• Terminal No. 4 for the number 1 cylinder.

• Terminal No. 5 for the number 2 cylinder.

• Terminal No. 20 for the number 3 cylinder.

• Terminal No. 21 for the number 4 cylinder.

• Terminal No. 52 for the number 5 cylinder.

• Terminal No. 53 for the number 6 cylinder.

Standard Wave Pattern

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

advanced when the engine speed is increased.

Observation condition

Function

Special pattern

Pattern height

Low

Pattern selector

Display

Engine r/min

Idle speed

16 15 14 13 12 11 10 9 8 7 6 5 4 3

2

1

32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17

48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33

64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49

AK700327AB

Power plant ECU
check harness connector

MB992110

AK700334

AB

TDC

5˚BTDC

ON

Time

OFF

Ignition power
transistor
control signal
wave pattern

Standard wave pattern

Ignition
timing

Dwell
section

5

10

0

0

2 Engine revolution (1 camshaft revolution)

(Volt)

Crankshaft position
sensor output
wave pattern