Mitsubishi Lancer Evolution IX. Manual — part 478

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-387

INTAKE CAMSHAFT POSITION 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. To check the state of the intake camshaft position

sensor output signal, observe its synchronicity
with the crankshaft position sensor output signal.

Alternate Method (Test harness not available)

1. Connect the oscilloscope special patterns pickup

to engine-ECU terminal No. 53 (When checking
the camshaft position sensor signal wave pattern).

Standard Wave Pattern

Observation condition

2 3

3

2

1

1

AK000840

Special patterns
pick-up

Oscilloscope

AD

Intake camshaft
position sensor
connector

Crank angle
sensor connector

Function

Special patterns

Pattern height

Low

Pattern selector

Display

Engine speed

Idle

AK403888

4

AC

2 engine revolutions (1 camshaft revolution)

(V)

0

4

0

(Time)

T

Standard wave pattern

Crank angle sensor
output wave pattern

Intake camshaft
position sensor
output wave pattern

phase angle

at retard angle

at advance angle

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-388

Wave Pattern Observation Points

For the engine at 2,500 r/min, make sure that the
time difference "T", between the output waveform of
the crank angle sensor and that of the intake cam-
shaft position sensor, is shorter on the rising edge.

Examples of Abnormal Wave Patterns

•

Example 1

Cause of problem
Sensor interface malfunction
Wave pattern characteristics
Rectangular wave pattern is output even when

the engine is not started.

•

Example 2

Cause of problem
Loose timing belt
Failure of the fuel pump camshaft

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

EXHAUST CAMSHAFT POSITION SEN-
SOR AND CRANK ANGLE SENSOR
Measurement Method

1. Disconnect the exhaust 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

exhaust 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. 50 (When checking
the exhaust camshaft position sensor signal wave
pattern).

2. Connect the oscilloscope special patterns pickup

to engine-ECU terminal No. 42 (When checking
the crank angle sensor signal wave pattern).

AKX01597

AKX01602

2 3

3

2

1

1

AK000840

Special patterns
pick-up

Oscilloscope

AE

Exhaust camshaft
position sensor
connector

Crank angle
sensor connector

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-389

Standard Wave Pattern

Observation condition

Wave Pattern Observation Points

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

Examples of Abnormal Wave Patterns

•

Example 1

Cause of problem
Sensor interface malfunction

Wave pattern characteristics
Rectangular wave pattern is output even when

the engine is not started.

•

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 (MPI)

13A-390

INJECTOR
Measurement Method

1. Disconnect the injector connector, and then

connect the special tool test harness (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. 9 (When checking the
No. 2 cylinder).

3. Connect the oscilloscope special patterns pickup

to engine-ECU terminal No. 24 (When checking
the No. 3 cylinder).

4. Connect the oscilloscope special patterns pickup

to engine-ECU terminal No. 2 (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