Mitsubishi Lancer Evolution IX. Manual - part 477

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-383

CHECK CHART FOR RESISTANCE AND 
CONTINUITY BETWEEN TERMINALS

1. Turn the ignition switch to "LOCK" (OFF) position.
2. Disconnect the engine-ECU connector.
3. Measure the resistance and check for continuity 

between the terminals of the engine-ECU 
harness-side connector while referring to the 
check chart.
NOTE: 

.

1. When measuring resistance and checking 

continuity, a harness for checking contact pin 
pressure should be used instead of inserting a 
test probe.

2. Checking need not be carried out in the order 

given in the chart.

CAUTION

If the terminals that should be checked are mis-
taken, or if connector terminals are not correctly 
shorted to earth, damage may be caused to the 
vehicle wiring, sensors, engine-ECU and/or ohm-
meter. Be careful to prevent this!
4. If the ohmmeter shows any deviation from the 

standard value, check the corresponding sensor, 
actuator and related electrical wiring, and the 
repair or replace.

5. After repair or replacement, recheck with the 

ohmmeter to confirm that the repair or 
replacement has corrected the problem.

83

A/C switch

Engine: Idle speed

Turn the A/C switch 
OFF

0.5 V or less

Turn the A/C switch 
ON (A/C compressor 
is operating)

System voltage

96

Transmission oil 
temperature sensor

Ignition switch: "ON"

Transmission oil 
temperature is 

−20°C

3.9 

− 4.5 V

Transmission oil 
temperature is 0

°C

3.2 

− 3.8 V

Transmission oil 
temperature is 20

°C

2.3 

− 2.9 V

Transmission oil 
temperature is 40

°C

1.3 

− 1.9 V

Transmission oil 
temperature is 60

°C

0.7 

− 1.3 V

Transmission oil 
temperature is 80

°C

0.3 

− 0.9 V

99

Ignition switch-IG

Ignition switch: "ON"

System voltage

Terminal 
No.

Check item

Check condition (Engine condition)

Normal condition

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-384

Engine-ECU Harness Side Connector Terminal Arrangement

Terminal 
No.

Inspection item

Normal condition (Check condition)

1 

− 47

No. 1 injector

2 

− 3 Ω (At 20°C)

9 

− 47

No. 2 injector

24 

− 47

No. 3 injector

2 

− 47

No. 4 injector

47 

− 48

Fuel pressure control solenoid valve

28 

− 36 Ω (At 20°C)

14 

− 47

Stepper motor coil (A1)

26 

− 33 Ω (At 20°C)

28 

− 47

Stepper motor coil (A2)

15 

− 47

Stepper motor coil (B1)

29 

− 47

Stepper motor coil (B2)

6 

− 47

EGR control solenoid valve

29 

− 35 Ω (At 20°C)

16 

− 47

Purge control solenoid valve 

30 

− 34 Ω (At 20°C)

41 

− 47

Waste gate solenoid valve

29 

− 35 Ω (At 20°C)

3 

− 47

Oxygen sensor heater (rear) 

11 

− 18 Ω (At 20°C)

26 

− 47

Oxygen sensor heater (front) 

4.5 

− 8.0 Ω (At 20°C)

33 

− 47

Oil feeder control valve

6.9 

− 7.9 Ω (At 20°C)

46 

− Body 

earth

ECU earth

Continuity (2 

Ω or less)

58 

− Body 

earth
42 

− 62

Intake air temperature sensor

13 

− 17 kΩ (When intake air temperature is −20°C)

5.3 

− 6.7 kΩ (When intake air temperature is 0°C)

2.3 

− 3.0 kΩ (When intake air temperature is 20°C)

1.0 

− 1.5 kΩ (When intake air temperature is 40°C)

0.56 

− 0.76 kΩ (When intake air temperature is 60°C)

0.30 

− 0.42 kΩ (When intake air temperature is 80°C)

42 

− 44

Engine coolant temperature sensor

14 

− 17 kΩ (When coolant temperature is −20°C)

5.1 

− 6.5 kΩ (When coolant temperature is 0°C)

2.1 

− 2.7 kΩ (When coolant temperature is 20°C)

0.9 

− 1.3 kΩ (When coolant temperature is 40°C)

0.48 

− 0.68 kΩ (When coolant temperature is 60°C)

0.26 

− 0.36 kΩ (When coolant temperature is 80°C)

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-385

INSPECTION PROCEDURE USING 
OSCILLOSCOPE

M1131154501483

The output signals of the sensors and the conditions 
of the actuation signals of the actuators can be 
inspected visually by observing the waveforms on 
the oscilloscope.

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 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. 61.

Standard Wave Pattern

Observation conditions

42 

− 96

Transmission oil temperature sensor

14 

− 17 kΩ (When transmission oil temperature is 

−20°C)
5.1 

− 6.5 kΩ (When transmission oil temperature is 

0

°C)

2.1 

− 2.7 kΩ (When transmission oil temperature is 

20

°C)

0.9 

− 1.3 kΩ (When transmission oil temperature is 

40

°C)

0.48 

− 0.68 kΩ (When transmission oil temperature is 

60

°C)

0.26 

− 0.36 kΩ (When transmission oil temperature is 

80

°C)

Terminal 
No.

Inspection item

Normal condition (Check condition)

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

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-386

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
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.

AK202334

(V)

10

T

T1

T2

0

Time

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

Standard wave pattern

Times T1 and T2 are equal.

AC

AK202335

(V)

10

T

0

Time

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

AB

AKX01597