Mitsubishi Pajero Pinin. Manual - part 125

MPI <4G9> – 

Troubleshooting

13C-86

Terminal
No.

Normal condition (Check condition)

Inspection item

72 – 92

Intake air temperature sensor

5.3 – 6.7 k

Ω

  (When intake air temperature is 0

_

C)

2.3 – 3.0 k

Ω

  (When intake air temperature is 20

_

C)

1.0 – 1.5 k

Ω

  (When intake air temperature is 40

_

C)

0.30 – 0.42 k

Ω

  (When intake air temperature is 80

_

C)

83 – 92

Engine coolant temperature sensor

5.1 – 6.5 k

Ω

  (When coolant temperature is 0

_

C)

2.1 – 2.7 k

Ω

  (When coolant temperature is 20

_

C)

0.9 – 1.3 k

Ω

  (When coolant temperature is 40

_

C)

0.26 – 0.36 k

Ω 

 (When coolant temperature is 80

_

C)

MPI <4G9> – 

Troubleshooting

13C-87

INSPECTION PROCEDURE USING AN ANALYZER

AIR FLOW SENSOR (AFS)

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 analyzer special patterns pickup to air flow
sensor connector terminal 3.

Alternate Method (Test harness not available)

1.

Connect the analyzer special patterns pickup to
engine-ECU terminal 90.

Standard Wave Pattern

Observation conditions

Function

Special patterns

Pattern height

Low

Pattern selector

Display

Engine r/min

Idle speed

Standard wave pattern

(V)
10

0

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

Times T1 and T2 are equal.

Time

T

T1

T2

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

Time

(V)

10

0

T

Wave Pattern Observation Points

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

Analyzer

Special
patterns
pickup

MPI <4G9> – 

Troubleshooting

13C-88

Examples of Abnormal Wave Patterns

D

Example 1

Cause of problem

Sensor interface malfunction

Wave pattern characteristics

Rectangular wave pattern is output even when the engine
is not started.

D

Example 2

Cause of problem

Damaged rectifier or vortex generation column

Wave pattern characteristics

Unstable wave pattern with non-uniform frequency.
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: MB991659) and
jumper wire in between. (All terminals should be
connected.)

2.

Connect the analyzer special patterns pickup to camshaft
position sensor terminal 2.

3.

Disconnect the crank angle sensor connector and connect
the special tool (test harness: MB991658) in between.

4.

Connect the analyzer special patterns pickup to crank
angle sensor terminal 3.

Alternate Method (Test harness not available)

1.

Connect the analyzer special patterns pickup to
engine-ECU terminal 88. (When checking the camshaft
position sensor signal wave pattern.)

2.

Connect the analyzer special patterns pickup to
engine-ECU terminal 89. (When checking the crank angle
sensor signal wave pattern.)

Standard Wave Pattern

Observation conditions

Function

Special patterns

Pattern height

Low

Pattern selector

Display

Engine r/min

Idle speed

Crank angle sensor connector

Camshaft position sensor connec-
tor

Analyzer

Special patterns
pick-up

MPI <4G9> – 

Troubleshooting

13C-89

Standard wave pattern

Crank angle 
sensor output
wave pattern

(V)

75

_

BTDC

2 engine revolutions 
(1 camshaft revolution)

5

_

BTDC

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

0

Camshaft posi-
tion sensor out-
put wave pat-
tern

TDC: Top dead centre

131

°

49

°

No. 1 TDC

No. 3 TDC

No. 4 TDC

No. 2 TDC

Time

0

56

°

34

°

Wave Pattern Observation Points

Check that cycle time T becomes shorter when the engine speed increases.

Examples of Abnormal Wave Patterns

D

Example 1

Cause of problem

Sensor interface malfunction

Wave pattern characteristics

Rectangular wave pattern is output even when the engine
is not started.

D

Example 2

Cause of problem

Loose timing belt
Abnormality in sensor disk

Wave pattern characteristics

Wave pattern is displaced to the left or right.