Mitsubishi Grandis. Manual - part 731

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-175

YES : 

Replace camshaft position sensor.

NO : 

Intermittent malfunction (Refer to GROUP 
00 

− How to Use 

Troubleshooting/Inspection Service Points 

P.00-5

).

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-176

Code No. P0403: Exhaust Gas Recirculation Control System

1

2 3

4

5 6

1

2

3

4

1

2

3

5

6 7 8 9

4

20

21 22

232425

2627

10111213

14 15

16 1718

19

AK305563

W-G

W-G

Engine
control
relay

Battery

4

3

2

B-15X

2

5

3

12

19

26

1

3

4

6

Exhaust gas
recirculation
(EGR) valve

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

EGR valve circuit

B-103

(MU802056)

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

C-110

(MU803802)

AB

SB 

L-Y

L-R

G-Y

1

11

9

J/C (4)

C-116

R-W

R-W

R-W

R-W

To engine-ECU <M/T> or
engine-A/T-ECU <A/T>

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-177

OPERATION

• Power is supplied to the EGR valve (terminal No. 

2 and No. 5) from the engine control relay 
(terminal No. 1).

• The engine-ECU <M/T> or engine-A/T-ECU 

<A/T> (terminal No. 3, No. 12, No. 19 and No. 26) 
makes the power transistor in the unit be in "ON", 
and that makes currents go on the EGR valve 
(terminal No. 1, No. 3, No. 4 and No. 6).

FUNCTION

• Based on the signal from engine-ECU <M/T> or 

engine-A/T-ECU <A/T>, the EGR valve (stepper 
motor) controls the EGR rate.

TROUBLE JUDGMENT

Check Condition

• Battery positive voltage is 10.3 V or higher.

Judgment Criterion

• The EGR valve motor coil surge voltage (battery 

positive voltage +2 V) is not detected for 3 
seconds.

PROBABLE CAUSE

• Failed EGR valve

• Open/short circuit in EGR valve circuit or loose 

connector contact

• Failed engine-ECU <M/T>

• Failed engine-A/T-ECU <A/T>

DIAGNOSIS PROCEDURE

STEP 1. Connector check: B-103 EGR valve 
connector

Q: Is the check result normal?

YES : 

Go to Step 2 .

NO : 

Repair or replace.

STEP 2. Check EGR valve itself.

• Check EGR control solenoid valve itself [Refer to 

GROUP 17 

− Emission Control System − 

Exhaust Gas Recirculation (EGR) System 

− EGR 

Valve (stepper motor) Check <4G69>

P.17-65

 .

Q: Is the check result normal?

YES : 

Go to Step 3 .

NO : 

Replace EGR valve (stepper motor).

STEP 3. Perform voltage measurement at B-103 
EGR valve connector.

• Disconnect connector, and measure at harness 

side.

• Ignition switch: ON

• Voltage between terminal No. 2, No. 5 and earth.

OK: System voltage

Q: Is the check result normal?

YES : 

Go to Step 5 .

NO : 

Go to Step 4 .

AK300987

1

2

3

4

5

6

AC

Connector: B-103

B-103 (GR)

Harness side connector

AK300987

1

2

3

4

5

6

AC

Connector: B-103

B-103 (GR)

Harness side connector

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-178

STEP 4. Connector check: B-15X engine control 
relay connector

Q: Is the check result normal?

YES : 

Check intermediate connector C-116, and 

repair if necessary. If intermediate 
connector is normal, check and repair 
harness between B-103 (terminal No. 2, No. 
5) EGR valve connector and B-15X 
(terminal No. 1) engine control relay 
connector.

• Check power supply line for 

open/short circuit.

NO : 

Repair or replace.

STEP 5. Perform voltage measurement at C-110 
engine-ECU connector or engine-A/T-ECU <A/T> 
connector.

• Disconnect connector, and measure at harness 

side.

• Ignition switch: ON

• Voltage between terminal No. 3, No. 12, No. 19, 

No. 26 and earth.

OK: System voltage

Q: Is the check result normal?

YES : 

Go to Step 7 .

NO : 

Go to Step 6 .

AK300967

2

1

3

4

AC

Harness side
connector

B-15X

Connector: B-15X

Relay box’s
triangle marks

AK300987

1

2

3

4

5

6

AC

Connector: B-103

B-103 (GR)

Harness side connector

AK305618AB

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

Connector: C-110

<L.H. drive vehicles>

<R.H. drive vehicles>

C-110 (GR)

C-110 (GR)

Harness side connector