Mitsubishi Lancer Evolution IX. Manual - part 425

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-175

Code No. P0403: Exhaust Gas Recirculation (EGR) Control Solenoid Valve

1

2

3

4

AK501814

1

2

2

3 4

5 6

7 8

9

11 12 13 14 15 16 17 18 19 20

30

21 22 23

24 25

26 27 28 29

3132 33

34 35

1

10

Engine control relay

B-12X

B-14

EGR control solenoid valve

1

2

2

6

6

Engine-ECU

EGR control solenoid valve circuit

G-O

G-O

R-Y

B-Y

B-Y

B-Y

R-Y

Battery

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

C-121

(MU803784)

B-101

6 <A-13> (*1) or
13 <C-31> (*2)

AB

NOTE

*1: L.H. drive vehicles
*2: R.H. drive vehicles

2

1

4

3

To engine-ECU

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-176

OPERATION

• Power is supplied to the EGR control solenoid 

valve (terminal No. 1) from the engine control 
relay (terminal No. 4).

• The engine-ECU (terminal No. 6) makes the 

power transistor in the unit be in "ON", and that 
makes currents go on the EGR control solenoid 
valve (terminal No. 2).

FUNCTION

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

the EGR control solenoid valve controls the oper-
ation of the EGR valve.

TROUBLE JUDGMENT

Check Condition

• The battery voltage is 10 V or more.

Judgment Criterion

• When the EGR control solenoid valve is turned to 

"LOCK" (OFF) position from "ON" position, none 
of solenoid coil surge voltage (system voltage of 
+2 V) is detected.

PROBABLE CAUSES

• Failed EGR control solenoid valve

• Open/short circuit in EGR control solenoid valve 

circuit or loose connector contact

• Failed engine-ECU

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-II/III actuator test

• Item No. 10: EGR control solenoid valve

OK: Operating sound can be heard and the 
valve vibrates.

Q: Is the check result normal?

YES : 

Intermittent malfunction (Refer to GROUP 

00 

− How to Use 

Troubleshooting/Inspection Service Points 

P.00-5

).

NO : 

Go to Step 2 .

STEP 2. Connector check: B-101 EGR control 
solenoid valve connector

Q: Is the check result normal?

YES : 

Go to Step 3 .

NO : 

Repair or replace the connector.

STEP 3. Perform resistance measurement at 
B-101 EGR control solenoid valve connector.

• Disconnect connector, and measure at solenoid 

valve side.

• Resistance between terminal No. 1 and No. 2.

OK: 29 

− 35 Ω (at 20°C)

Q: Is the check result normal?

YES : 

Go to Step 4 .

NO : 

Replace the EGR control solenoid valve.

AK305024

1

2

AB

Connector : B-101

Harness side 
connector

B-101(BR)

AK305024

1

2

AB

Connector : B-101

Harness side 
connector

B-101(BR)

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-177

STEP 4. Perform voltage measurement at B-101 
EGR control solenoid valve connector.

• 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 6 .

NO : 

Go to Step 5 .

STEP 5. Connector check: B-12X engine control 
relay connector

Q: Is the check result normal?

YES : 

Check intermediate connector B-14, and 

repair if necessary. If intermediate 
connector is normal, check and repair 
harness between B-101 (terminal No. 1) 
EGR control solenoid valve connector and 
B-12X (terminal No. 4) engine control relay 
connector.

• Check power supply line for 

open/short circuit.

NO : 

Repair or replace the connector.

AK305024

1

2

AB

Connector : B-101

Harness side 
connector

B-101(BR)

AK305003

2

1

3

4

AB

Connector : B-12X

B-12X

Harness side 
connector

Relay box’s
triangle marks

AK305024

1

2

AB

Connector : B-101

Harness side 
connector

B-101(BR)

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-178

STEP 6. Perform voltage measurement at C-121 
engine-ECU connector.

• Disconnect connector, and measure at harness 

side.

• Ignition switch: "ON"

• Voltage between terminal No. 6 and earth.

OK: System voltage

Q: Is the check result normal?

YES : 

Go to Step 8 .

NO : 

Go to Step 7 .

STEP 7. Connector check: C-121 engine-ECU 
connector

Q: Is the check result normal?

YES : 

Check intermediate connector B-14, and 

repair if necessary. If intermediate 
connector is normal, check and repair 
harness between B-101 (terminal No. 2) 
EGR control solenoid valve connector and 
C-121 (terminal No. 6) engine-ECU 
connector.

• Check output line for open/short 

circuit.

NO : 

Repair or replace the connector.

AK501995

2

3

4

5

6

7

8

9

11

12

13

14

15

16

17

18

19

20

30

21

22

23

24

25

26

27

28

29

31

32

33

34

35

1

10

AB

Connector: C-121

C-121 (GR)

C-121 (GR)

Harness side connector

<L. H. drive vehicles>

<R. H. drive vehicles>

AK501995

2

3

4

5

6

7

8

9

11

12

13

14

15

16

17

18

19

20

30

21

22

23

24

25

26

27

28

29

31

32

33

34

35

1

10

AB

Connector: C-121

C-121 (GR)

C-121 (GR)

Harness side connector

<L. H. drive vehicles>

<R. H. drive vehicles>

AK305024

1

2

AB

Connector : B-101

Harness side 
connector

B-101(BR)