Mitsubishi Outlander (2003+). Manual — part 109

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MFI)

13A-299

AIR FLOW SENSOR

Measurement Method

1. Disconnect the air flow sensor connector, and

connect the special tool Test harness (MB991709)
in between (All terminals should be connected).

2. Connect the oscilloscope special patterns pickup

to air flow sensor connector terminal No. 3.

Alternate Method (Test harness not available)
1. Connect the oscilloscope special patterns pickup

to engine-ECU terminal No. 90.

Standard Wave Pattern

Observation conditions

Wave Pattern Observation Points
Check that cycle time T becomes shorter and the fre-
quency increases when the engine speed is
increased.

AK000786

4 5 6

1 2 3

7

AE

Special
patterns
pickup

Oscilloscope

Function

Special patterns

Pattern height

Low

Pattern selector

Display

Engine speed

Idle

AK202334

(V)

10

T

T1

T2

0

Time

The time (cycle time) T is reduced when
the amount of intake air inereases.

Standard wave pattern

Times T1 and T2 are equal.

AB

AK202335

(V)

10

T

0

Time

Observation conditions (from conditions above engine is increased by racing.)

AB

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MFI)

13A-300

Examples of Abnormal Wave Patterns

œ

Example 1

Cause of problem
Sensor interface malfunction

Wave pattern characteristics
Rectangular wave pattern is output even when

the engine is not started.

œ

Example 2

Cause of problem
Damaged rectifier or vortex generation column

Wave pattern characteristics
Unstable wave pattern with non-uniform fre-

quency. However, when an ignition leak
occurs during acceleration, the wave pattern
will be distorted temporarily, even if the air
flow sensor is normal.

CAMSHAFT POSITION SENSOR AND
CRANK ANGLE SENSOR

Measurement Method

1. Disconnect the camshaft position sensor

connector and connect the special tool Test
harness (MB991709) in between (All terminals
should be connected).

2. Connect the oscilloscope special pattern pickup to

camshaft position sensor terminal No. 2.

3. Disconnect the crank angle sensor connector and

connect the special tool Test harness
(MD998478) in between.

4. Connect the oscilloscope special patterns pickup

to crank angle sensor terminal No. 2.

Alternate Method (Test harness not available)
1. Connect the oscilloscope special patterns pickup

to engine-ECU terminal No. 88 (When checking
the camshaft position sensor signal wave
pattern).

2. Connect the oscilloscope special patterns pickup

to engine-ECU terminal No. 89 (When checking
the crank angle sensor signal wave pattern).

AKX01597

2 3

3

2

1

1

AK000840

Special patterns
pick-up

Oscilloscope

AC

Camshaft position
sensor connector

Crank angle
sensor connector

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MFI)

13A-301

Standard Wave Pattern

Observation condition

Wave Pattern Observation Points
Check that cycle time T becomes shorter when the
engine speed increases.

Examples of Abnormal Wave Patterns

œ

Example 1

Cause of problem
Sensor interface malfunction

Wave pattern characteristics
Rectangular wave pattern is output even when

the engine is not started.

œ

Example 2

Cause of problem
Loose timing belt
Abnormality in sensor disk

Wave pattern characteristics
Wave pattern is displaced to the left or right.

Function

Special patterns

Pattern height

Low

Pattern selector

Display

Engine speed

Idle

AK202336

The time (cycle time)
T is reduced when the
engine speed increases

Time

0

0

Crank angle
sensor output
wave pattern

Camshaft position
sensor output
wave pattern

TDC: Top dead centre

Standard Wave Pattern

No.1 TDC

No.2 TDC

No.3 TDC

No.4 TDC

2 engine revolutions
(1 camshaft revolution)

75˚ BTDC

5˚ BTDC

(V)

AB

AKX01597

AKX01602

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MFI)

13A-302

INJECTOR

Measurement Method

1. Disconnect the injector connector, and then

connect the special tool Test harness set
(MB991348) in between (All terminals should be
connected).

2. Connect the oscilloscope special patterns pickup

to terminal No. 2 of the injector connector.

Alternate Method (Test harness not available)
1. Connect the oscilloscope special patterns pickup

to engine- ECU terminal No. 1 (When checking
the No. 1 cylinder).

2. Connect the oscilloscope special patterns pickup

to engine-ECU terminal No. 14 (When checking
the No. 2 cylinder).

3. Connect the oscilloscope special patterns pickup

to engine-ECU terminal No. 2 (When checking the
No. 3 cylinder).

4. Connect the oscilloscope special patterns pickup

to engine-ECU terminal No. 15 (When checking
the No. 4 cylinder).

Standard Wave Pattern

Observation conditions

AK101807

1

2

AC

Special
patterns
pickup

Oscilloscope

Function

Special patterns

Pattern height

Variable

Variable knob

Adjust while viewing the
wave pattern

Pattern selector

Display

Engine speed

Idle

AK202347AB

(V)

50

0

Power
voltage

Solenoid back
electromotive
force
(Approx.7×10V)

Drive signal: ON

Drive signal: OFF

Point B
Injector drive
time

Point A.

Standard wave pattern

Time