Mitsubishi Colt Ralliart. Manual - part 91

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI) <4A9>

13A-318

STEP 5. Connector check: A-08 engine-ECU 
connector or engine-CVT-ECU connector

Q: Is the check result normal?

YES : 

Go to Step 6 .

NO : 

Repair or replace the connector.

STEP 6. Perform voltage measurement at A-08 
engine-ECU connector or engine-CVT-ECU 
connector.

• Disconnect the engine-ECU connector or 

engine-CVT-ECU connector and connect the 
special tool power plant ECU check harness 
(MB991987), and then measure the voltage at 
check connector.

• Voltage between terminal No. 128 and the earth.

OK:

System voltage (Brake pedal: Depressed)
1 V or less (Brake pedal: Released)

Q: Is the check result normal?

YES : 

Go to Step 8 .

NO : 

Go to Step 7 .

AK402725

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127

128

129

72 71

74 73

76 75

R

AG

A-08

Connector: 

A-08

Harness side connector

Battery

Engine-ECU <M/T> or
engine-CVT-ECU <CVT>

AK402725

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125

126

127

128

129

72 71

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76 75

R

AH

A-08

Connector: 

A-08

A-08 Special tool power plant ECU check 
harness

Battery

Engine-ECU <M/T> or
engine-CVT-ECU <CVT>

Main

Index

Group

TOC

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI) <4A9>

13A-319

STEP 7. Check harness between B-27 (terminal 
No. 1) stop lamp switch connector and A-08 
(terminal No. 128) engine-ECU connector or 
engine-CVT-ECU connector. 

• Check output line open/short circuit and damage.

Q: Is the check result normal?

YES : 

For a short circuit, check and repair harness 

and the connector for the stop lamp switch 
output signal.

NO : 

Repair.

STEP 8. M.U.T.-III data list

• Refer to Data List Reference Table 

P.13A-331

.

a. Item 67: Stop lamp switch

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 <M/T> or 
engine-CVT-ECU <CVT>.

2

1

3

4

AK402068AC

Connector: B-27

B-27

B-27 Harness side

connector

AK402725

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109

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134

135

136

122

123

124

125

126

127

128

129

72 71

74 73

76 75

R

AG

A-08

Connector: 

A-08

Harness side connector

Battery

Engine-ECU <M/T> or
engine-CVT-ECU <CVT>

Main

Index

Group

TOC

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI) <4A9>

13A-320

Inspection Procedure 28: Ignition circuit system

AK402687

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4 5 6

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1

2 3

1

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1

2 3

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1213

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L

10

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52 53 54 555657585960616263646566

38 39 404142434445464748495051

22 23 24 252627282930313233343536

7

5

3

1

6

4

2

LOCK

ACC

IG1 IG2

ST

10A

Ignition coil 1

Engine-ECU <M/T> or
engine-CVT-ECU <CVT>

A-135

(MU802053)

A-127

(MU802053)

A-126

(MU802053)

A-123

(MU802053)

Ignition coil 2

Ignition coil 3

Ignition coil 4

2

3

10

25

40

55

Noise 
condenser

A-111

Ignition switch

L-B

B-W

B-W

B-W

B-W

B-W

B-W

W

W-G

W-B

W-L

B

B

B

B

2

3

15

B-112

A-17

3

B-129

J/B

Ignition Circuit

A-114

AD

Spark
plug

2

1

1

1

1

1

3

Spark
plug

2

3

Spark
plug

2

3

Spark
plug

B141

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  Pu: Purple

Main

Index

Group

TOC

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI) <4A9>

13A-321

OPERATION

• The battery voltage is applied to the ignition coil 

(terminal No. 1) from the ignition switch and is 
earthed to the vehicle body from the ignition coil 
(terminal No. 2).

• A power voltage of 12 V is applied to the ignition 

coil output terminal (terminal No. 3) from the 
engine-ECU <M/T> or engine-CVT-ECU <CVT> 
(terminals No. 10, No. 25, No. 40 and No. 55).

FUNCTION

• When the engine-ECU <M/T> or 

engine-CVT-ECU <CVT> makes the power tran-
sistor in the unit be in OFF position, the battery 
voltage in the unit is applied to the power transis-
tor unit, and that makes the power transistor unit 
be in ON position. The engine-ECU <M/T> or 
engine-CVT-ECU <CVT> makes the power tran-
sistor in the unit be in ON, and that makes the 
power transistor unit be in OFF position.

• In response to the signal from the engine-ECU 

<M/T> or engine-CVT-ECU <CVT>, the power 
transistor unit is in ON position. The primary cur-
rent is going to the ignition coil. When the power 
transistor unit is in OFF position, the primary cur-
rent is interrupted and high voltage is generated 
in the secondary coil.

PROBABLE CAUSES

• Failed ignition coil

• Failed spark plug

• Open/short/damaged circuit in ignition primary 

circuit or loose connector contact

• Failed engine-ECU <M/T> or engine-CVT-ECU 

<CVT>

DIAGNOSIS PROCEDURE

STEP 1. Connector check: A-123, A-126, A-127 
and A-135 ignition coil connectors

Q: Is the check result normal? 

YES : 

Go to Step 2 .

NO : 

Repair or replace the connector.

STEP 2. Check ignition coil itself.

• Check ignition coil itself (Refer to GROUP 16 − 

Ignition System 

− On-vehicle Service − Ignition 

Coil Check 

P.16-34

).

Q: Is the check result normal? 

YES : 

Go to Step 3 .

NO : 

Replace ignition coil.

STEP 3. Perform voltage measurement at A-123, 
A-126, A-127 and A-135 ignition coil connectors.

• Disconnect connector, and measure at harness 

side.

• Ignition switch: ON 

• Voltage between terminal No. 1 and earth.

OK: System voltage

Q: Is the check result normal? 

YES : 

Go to Step 5 .

NO : 

Go to Step 4 .

AK402013

1

2

3

A-135 (DG) A-127 (DG)

A-126 (DG)

A-123 (DG)

Connector: A-123, A-126, A-127, A-135

AC

Harness side
connector

AK402013

1

2

3

A-135 (DG) A-127 (DG)

A-126 (DG)

A-123 (DG)

Connector: A-123, A-126, A-127, A-135

AC

Harness side
connector

Main

Index

Group

TOC