Mitsubishi Lancer Evolution IX. Manual - part 440

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-235

PROBLEM SYMPTOMS TABLE

A/C performance

Poor A/C Performance

The temperature of air cooling from 
A/C is not efficient or very far from 
the target temperature.

22

Items

Trouble symptom

Inspection 
procedure 
No.

Inspection 
procedure 
No.

Trouble symptom

Reference 
page

1

Communication with all system is not possible

P.13A-237

2

Communication with engine-ECU only is not possible

P.13A-240

3

The engine warning lamp does not illuminate right after the ignition switch is 
turned "ON" position

P.13A-243

4

The engine warning lamp remains illuminating and never goes out

P.13A-252

5

Starting impossible (No initial combustion)

P.13A-255

6

Starting impossible (Starter operative but no initial combustion)

P.13A-262

7

Starting impossible (Initial combustion but no complete combustion)

P.13A-264

Starting impossible (Long time to start)

8

Unstable idling (Rough idling, hunting)

P.13A-268

Improper idling speed (Too high or too low)
Engine stalls during idling (Die out)

9

The engine stalls when starting the car (pass out)

P.13A-275

10

The engine stalls when decelerating

P.13A-277

11

Engine does not revolve up

P.13A-279

12

Hesitation, sag

P.13A-281

Poor acceleration
Stumble
Surge

13

The feeling of impact or vibration when accelerating

P.13A-283

14

The feeling of impact or vibration when decelerating

P.13A-285

15

Knocking

P.13A-285

16

Ignition timing offset

P.13A-287

17

Run on (Dieseling)

P.13A-288

18

Odor, white smoke, black smoke, high-concentration CO/HC during idling

P.13A-289

19

Battery rundown

P.13A-291

20

Overheating

P.13A-296

21

Abnormal rotation of fan motor

P.13A-297

22

Poor A/C performance

P.13A-300

23

Engine-ECU power supply, engine control relay, ignition switch-IG1 system

P.13A-302

24

Fuel pump system

P.13A-313

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-236

25

Radiator fan control relay system

P.13A-324

26

Condenser fan control relay system

P.13A-330

27

A/C switch system

P.13A-341

28

A/C compressor relay system

P.13A-344

29

A/C load signal system

P.13A-352

30

Ignition circuit system <L.H. drive vehicles>

P.13A-356

31

Ignition circuit system <R.H. drive vehicles>

P.13A-363

Inspection 
procedure 
No.

Trouble symptom

Reference 
page

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-237

SYMPTOM PROCEDURES

Inspection Procedure 1: Communication with All System is not Possible

OPERATION

• Battery voltage is applied to diagnosis connector 

(terminal No.16).

• Diagnosis connector (terminals No. 4 and 5) are 

earthed to the vehicle body.

COMMENTS ON TROUBLE SYMPTOM

• Failure is possibly caused by failed power supply 

circuit or failed earthing circuit of diagnosis con-
nector.

1 2 3 4 5 6

12

11

10

1516

14

13

9

7 8

AK305249

15

15A

Fusible link (1)

C-14

Diagnosis connector

1

C-211

C-214

W-R

W-R

B

B

12

16

4

5

J/B

Diagnosis connector circuit

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

AC

1

C-126

G-R (*1) or
W (*2)

NOTE

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

TROUBLESHOOTING

MULTIPORT FUEL INJECTION (MPI)

13A-238

PROBABLE CAUSES

• Failed diagnosis connector

• Open/short circuit in diagnosis connector circuit. 

• Failed M.U.T.-II/III

DIAGNOSIS PROCEDURE

STEP 1. Connector check: C-14 diagnosis 
connector

Q: Is the check result normal?

YES : 

Go to Step 2 .

NO : 

Repair or replace the connector.

STEP 2. Perform resistance measurement at C-14 
diagnosis connector.

• Disconnect connector, and measure at harness 

side.

• Resistance between terminal No. 4 and earth, 

also between terminal No. 5 and earth.

OK: 2 

Ω or less

Q: Is the check result normal?

YES : 

Go to Step 3 .

NO : 

Check and repair harness between C-14 

(terminal No. 4) diagnosis connector and 
body earth, also between C-14 (terminal No. 
5) diagnosis connector and body earth.

• Check earthing line for open circuit 

and damage.

STEP 3. Perform voltage measurement at C-14 
diagnosis connector.

• Disconnect connector, and measure at the har-

ness side.

• Voltage between terminal No. 16 and earth.

OK: System voltage

Q: Is the check result normal?

YES : 

Go to Step 4 .

NO : 

Check intermediate connectors C-126, C-211 

and C-214, and repair if necessary. If 
connectors are normal, check and repair 
harness between C-14 (terminal No. 16) 
diagnosis connector and battery.

• Check power supply line for 

open/short circuit.

STEP 4. Replace M.U.T.-II/III.

• After replacing the M.U.T.-II/III, re-check the trou-

ble symptoms.

Q: Does trouble symptom persist?

YES : 

Go to Step 5 .

NO : 

The check is end.

AK203591

1 2 3 4 5 6

12

11

10

1516

14

13

9

7 8

AD

Connector: C-14

Harness side connector

C-14 (B)

AK203591

1 2 3 4 5 6

12

11

10

1516

14

13

9

7 8

AD

Connector: C-14

Harness side connector

C-14 (B)

AK203591

1 2 3 4 5 6

12

11

10

1516

14

13

9

7 8

AD

Connector: C-14

Harness side connector

C-14 (B)