Mitsubishi Colt Ralliart. Manual - part 685

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI) <4G1>

13B-65

Code No. P0130: Oxygen Sensor (front) System

OPERATION

• The sensor signal is input to the engine-ECU (ter-

minal No. 34) from the oxygen sensor (terminal 
No. 1).

• The oxygen sensor (terminal No. 2) is earthed to 

the engine-ECU (terminal No. 49).

FUNCTION

• The oxygen sensor (front) converts the concen-

tration of oxygen in the exhaust emission into a 
voltage and inputs the signal to the engine-ECU.

• When the mixture is richer than the theoretical 

air-fuel ratio, the oxygen sensor (front) outputs a 
voltage of about 1 V. For leaner mixture, the sen-
sor outputs a voltage of about 0 V.

• In response to the signal, the engine-ECU con-

trols the fuel injection amount to make the mix-
ture equal to the theoretical air-fuel ratio.

AK600606

1 2

4

3

19

21

20

18

17

16

15

14

1213

11

8 9

L

10

37
52 53 54 555657585960616263646566

38 39 404142434445464748495051

22 23 24 252627282930313233343536

7

5

3

1

6

4

2

Oxygen sensor (front)

Y

GR

From engine control relay

3

2

4

1

49

34

    A-122
MU802083

A-114

Engine-ECU

To engine-ECU

AB

Wire colour code
B: Black  LG: Light green  G: Green  L: Blue  W: White  Y: Yellow  SB: Sky blue  BR: Brown  O: Orange  GR: Gray
R: Red  P: Pink  V: Violet  P: Purple

Oxygen Sensor (front) Circuit 

Main

Index

Group

TOC

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI) <4G1>

13B-66

TROUBLE JUDGEMENT

Check Conditions

• 3 minutes later from when engine starts

• For 5 seconds, engine coolant temperature is 

more than 80

°C.

• For 5 seconds, engine speed is more than 

1,200r/min.

• The volume efficiency for 5 seconds is 50% or 

more. 

Judgement Criterion

• When 5 V is applied to oxygen sensor (front) out-

put line via register, engine-ECU-interface output 
voltage is more than 4.0 V.

Check Conditions

• Engine speed is more than 1,500 r/min and is 

less than 3,000 r/min.

• Engine coolant temperature is more than 60°C.

• The volume efficiency is more than 20% and is 

less than 45%.

• Within the range of air-fuel ratio feed back opera-

tion

Judgement Criterion

• The average output frequency of the oxygen sen-

sor (front) is 3 times or less for 12 seconds.

PROBABLE CAUSES

• Failed oxygen sensor (front)

• Open/short circuit or damage in oxygen sensor 

circuit, or loose connector contact

• Failed engine-ECU

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III data list

• Refer to Data List Reference Table 

P.13B-335

.

a. Item 11: Oxygen sensor (front)

Q: Is the check result normal?

YES : 

Intermittent malfunction (Refer to GROUP 

00 

− How to Use 

Troubleshooting/Inspection Service Points 

− 

How to Cope with Intermittent Malfunctions 

P.00-13

).

NO : 

Go to Step 2 .

STEP 2. Connector check: A-122 oxygen sensor 
(front) connector

Q: Is the check result normal?

YES : 

Go to Step 3 .

NO : 

Repair or replace.

AK402087

Connector: A-122

Harness side 

connector

A-122(G)

AD

Oxygen sensor (front)

Main

Index

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TOC

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI) <4G1>

13B-67

STEP 3. Perform resistance measurement at 
A-122 oxygen sensor (front) connector.

• Disconnect connector and measure at harness 

side.

• Resistance between terminal No. 2 and earth.

OK: Continuity (2 

Ω or less)

Q: Is the check result normal?

YES : 

Go to Step 7 .

NO : 

Go to Step 4 .

STEP 4. Connector check: A-114 engine-ECU 
connector

Q: Is the check result normal?

YES : 

Go to Step 5 .

NO : 

Repair or replace.

AK402087

Connector: A-122

Harness side 

connector

A-122(G)

AD

Oxygen sensor (front)

AK402745

6

4

2

5

3

1

9

7

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52

53

54

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58

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60

61

62

63

64

65

66

L

AF

A-114

Connector: 

A-114

Harness side connector

Engine-ECU

Battery

Main

Index

Group

TOC

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI) <4G1>

13B-68

STEP 5. Check harness between A-122 (terminal 
No. 2) oxygen sensor (front) connector and A-114 
(terminal No. 49) engine-ECU connector.

• Check earthing line for open circuit and damage.

Q: Is the check result normal?

YES : 

Go to Step 6 .

NO : 

Repair.

STEP 6. M.U.T.-III data list

• Refer to Data List Reference Table 

P.13B-335

.

a. Item 11: Oxygen sensor (front)

Q: Is the check result normal?

YES : 

Intermittent malfunction (Refer to GROUP 

00 

− How to Use Troubleshooting/Inspection 

Service Points 

− How to Cope with 

Intermittent Malfunctions 

P.00-13

).

NO : 

Replace engine-ECU.

STEP 7. Perform voltage measurement at A-122 
oxygen sensor (front) connector.

• Use special tool test harness (MB991658) to con-

nect connector, and measure at pick-up harness.

• Engine: After warm-up

• Ignition switch: ON

• Voltage between terminal No. 2 and earth.

OK: 0.5 V or less

Q: Is the check result normal?

YES : 

Go to Step 9 .

NO : 

Go to Step 8 .

AK402087

Connector: A-122

Harness side 

connector

A-122(G)

AD

Oxygen sensor (front)

AK402745

6

4

2

5

3

1

9

7

8

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

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28

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47

48

49

50

51

52

53

54

55

56

57

58

59

60

61

62

63

64

65

66

L

AF

A-114

Connector: 

A-114

Harness side connector

Engine-ECU

Battery

AK402087

Connector: A-122

Harness side 

connector

A-122(G)

AD

Oxygen sensor (front)

Main

Index

Group

TOC