Mitsubishi Lancer Evolution IX. Manual - part 476

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-379

CHECK AT THE ENGINE-ECU 
TERMINALS

M1131153500744

TERMINAL VOLTAGE CHECK CHART

1. Connect a needle-nosed wire probe to a voltmeter 

probe.

2. Insert the needle-nosed wire probe into each of 

the engine-ECU connector terminals from the wire 
side, and measure the voltage while referring to 
the check chart.

NOTE: 

.

1. Make the voltage measurement with the 

engine-ECU connector connected.

2. You may find it convenient to pull out the 

engine-ECU to make it easier to reach the 
connector terminals.

3. The checks can be carried out off the order 

given in the chart.

CAUTION

Short-circuiting the positive (+) probe between a 
connector terminal and earth could damage the 
vehicle wiring, the sensor, engine-ECU or all of 
them. Be careful to prevent this!
3. If voltmeter shows any division from standard 

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

4. After repair or replacement, recheck with the 

voltmeter to confirm that the repair has corrected 
the problem.

21

Fan 
controller

Actuate fan 
motor

• Ignition switch: "ON"

• A/C switch: ON

Fan motor is 
rotated

Procedure 
No. 25

P.13A-32
4

37

Condenser 
fan (high)

Condenser fan 
motor is driven.

Ignition switch: "ON"

Fan motor 
rotates at high 
speed

Procedure 
No. 26

P.13A-33
0

38

Condenser 
fan (low)

Condenser fan 
motor is driven.

Ignition switch: "ON"

Fan motor 
rotates at low 
speed

Item 
No.

Inspection 
item

Drive content

Inspection conditions

Normal 
condition

Code No. 
/Inspection 
procedure 
No.

Reference 
page

AK201749AB

Needle-nosed  wire  probe 

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-380

Engine-ECU Connector Terminal Arrangement

Terminal 
No.

Check item

Check condition (Engine condition)

Normal condition

1

No. 1 injector

While engine is idling after having warmed 
up, suddenly depress the accelerator pedal.

From 11 

− 14 V, 

momentarily drops slightly

9

No. 2 injector

24

No. 3 injector

2

No. 4 injector

3

Oxygen sensor 
heater (front) 

Engine: Idling after warming up

1 V or less

Engine r/min: 5,000 r/min

System voltage

6

EGR control 
solenoid valve

Ignition switch: "ON"

System Voltage

While engine is idling, suddenly depress the 
accelerator pedal.

From system voltage, 
momentarily drops

8

Alternator G terminal

• Engine: Warm, idle (radiator fan: OFF)

• Headlamp: OFF → ON

• Stop lamp: OFF → ON

• Rear defogger switch: OFF → ON

Voltage increases by 0.2 

− 

3.5 V

11

Ignition coil 

− No. 1, 

No. 4

Engine r/min: 3,000 r/min

0.3 

− 3.0 V

12

Ignition coil 

− No. 2, 

No. 3

14

Stepper motor coil 
<A1>

• Engine: Soon after the warmed up engine 

is started

• A/C switch: OFF → ON (A/C compressor 

is operating)

• Headlight switch: OFF → ON

System voltage 

⇔ 1V or 

less (Changes repeatedly)

28

Stepper motor coil 
<A2>

15

Stepper motor coil 
<B1>

29

Stepper motor coil 
<B2>

16

Purge control 
solenoid valve

Ignition switch: "ON"

System voltage

Running at 3,500 r/min while engine is 
warming up after having been started.

1 V or less

18

Fan controller

Radiator fan is not operating

0 

− 0.3 V

Radiator fan is operating

0.7 V or more

19

Air flow sensor reset 
signal

Engine: Idle speed

0 

− 1 V

Engine r/min: 3,000 r/min

6 

− 9 V

20

A/C relay 

• Engine: Idle speed

• A/C switch: OFF → ON (A/C compressor 

is operating)

System voltage or 
Momentarily 6 V or more 
→ 1 V or less

21

Fuel pump relay 2

Ignition switch: "ON"

System voltage

Engine: Idle speed

1 V or less

22

Engine warning lamp Ignition switch: "LOCK" (OFF) 

→ "ON"

1 V or less 

→ System 

voltage (After several 
seconds have elapsed)

26

Oxygen sensor 
heater (rear) 

Engine: Idling after warming up

1 V or less

Engine: Racing

System voltage

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-381

30

Condenser fan 
motor relay (high)

Fan inactive state (Engine coolant 
temperature: 90

°C or less)

System voltage

Fan high-speed rotation state (Engine 
coolant temperature: 105

°C or less)

1 V or less

31

Condenser fan 
motor relay (low)

Fan inactive state (Engine coolant 
temperature: 90

°C or less)

System voltage

Fan low-speed rotation state (Engine coolant 
temperature: 95 

− 100°C or less)

1 V or less

33

Oil feeder control 
valve

Ignition switch: "ON"

System voltage

High-load running

4.0 

− 10 V

41

Waste gate solenoid 
valve

Ignition switch: "ON"

System voltage

Engine: After warm-up, idle operation (When 
using premium gasoline)

1 V or less

42

Sensor impressed 
voltage

Ignition switch: "ON"

4.9 

− 5.1 V

43

Crank angle sensor

Engine: Cranking

0.4 

− 4.0 V

Engine: Idling speed

1.5 

− 2.5 V

44

Engine coolant 
temperature sensor

Ignition switch: "ON"

When engine coolant 
temperature is 

−20°C

3.9 

− 4.5 V

When engine coolant 
temperature is 0

°C

3.2 

− 3.8 V

When engine coolant 
temperature is 20

°C

2.3 

− 2.9 V

When engine coolant 
temperature is 40

°C

1.3 

− 1.9 V

When engine coolant 
temperature is 60

°C

0.7 

− 1.3 V

When engine coolant 
temperature is 80

°C

0.3 

− 0.9 V

45

Tachometer signal

Engine r/min: 3,000 r/min

0.3 

− 3.0 V

47

Power supply

Ignition switch: "ON"

System voltage

59
48

Fuel pressure 
control solenoid 
valve

Ignition switch: "ON"

System voltage

Engine: Cranking 

→ Idle operation (within 

approximately 2 minutes or less)

1 V or less 

→ System 

voltage

50

Exhaust camshaft 
position sensor

Engine: Cranking

0.4 

− 3.0 V

Engine: Idling

1.5 

− 3.0 V

51

Barometric pressure 
sensor

Ignition switch: "ON"

Altitude: 0 m

3.8 

− 4.2 V

Altitude: 600 m

3.5 

− 3.9 V

Altitude: 1,200 m

3.3 

− 3.7 V

Altitude: 1,800 m

3.0 

− 3.4 V

Terminal 
No.

Check item

Check condition (Engine condition)

Normal condition

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-382

52

Alternator FR 
terminal

• Engine: Warm, idle (radiator fan: OFF)

• Headlamp: OFF → ON

• Stop lamp: OFF → ON

• Rear defogger switch: OFF → ON

Voltage decreases

53

Intake camshaft 
position sensor

Engine: Cranking

0.4 

− 3.0 V

Engine: Idling

1.5 

− 3.0 V

54

Power steering fluid 
pressure switch

Engine: Idling after 
warming up

When steering wheel 
is stationary

System voltage

When steering wheel 
is turned

1 V or less

55

Fuel pump relay 3

While engine is idling, suddenly depress the 
accelerator pedal.

Temporarily rises slightly 
from 1 V or less.

57

Control relay (Power 
supply)

Ignition switch: "LOCK" (OFF)

System voltage

Ignition switch: "ON"

1 V or less

60

Backup power 
supply

Ignition switch: "LOCK" (OFF)

System voltage

61

Air flow sensor

Engine: Idle speed

2.2 

− 3.2 V

Engine r/min: 2,500 r/min

62

Intake air 
temperature sensor

Ignition switch: "ON"

When intake air 
temperature is 

−20°C

3.8 

− 4.4 V

When intake air 
temperature is 0

°C

3.2 

− 3.8 V

When intake air 
temperature is 20

°C

2.3 

− 2.9 V

When intake air 
temperature is 40

°C

1.5 

− 2.1 V

When intake air 
temperature is 60

°C

0.8 

− 1.4 V

When intake air 
temperature is 80

°C

0.4 

− 1.0 V

65

A/C load signal

Refer to GROUP 55 - Troubleshooting (Inspection at the Automatic 
compressor - ECU Terminal)

68

Ignition switch-ST

Engine: Cranking

8 V or more

71

Oxygen sensor 
(front)

Engine: Running at 2,500 r/min after warmed 
up (Check using a digital type voltmeter)

0 

⇔ 0.8 V (Changes 

repeatedly)

73

Oxygen sensor 
(rear)

Engine: Idling after warmed up (Check using 
a digital type voltmeter)

0 

⇔ 0.6 V (Changes 

repeatedly)

78

Throttle position 
sensor

Ignition switch: "ON"

Set throttle valve to 
idle Position

0.535 

− 0.735 V

Fully open throttle 
valve

4.4 

− 5.3 V

80

Vehicle speed 
sensor

• Ignition switch: "ON"

• Move the vehicle forword slowly

0 

⇔ 5 V Changes 

repeatedly

Terminal 
No.

Check item

Check condition (Engine condition)

Normal condition