Mitsubishi Lancer Evolution X. Manual - part 376

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-569

STEP 6. Check for continuity at clutch pedal position 
switch harness side connector C-49.
(1) Disconnect the connector C-49 and measure the harness 

side.

(2) Check for the continuity between terminal No. 1 and 

ground.

• Should be less than 2 ohms.

Q: Does continuity exist?

YES : Go to Step 7.
NO :  Repair harness wire between clutch pedal position 

switch connector C-49 terminal No. 1 and ground 
because of harness damage. Then go to Step 9.

STEP 7. Check harness connector B-10 at ECM for 
damage.
Q: Is the harness connector in good condition?

YES : Go to Step 8.
NO :  Repair or replace it. Refer to GROUP 00E, Harness 

Connector Inspection 

P.00E-2

. Then go to Step 9.

STEP 8. Check for harness damage between clutch pedal 
position switch connector C-49 (terminal No. 2) and ECM 
connector B-10 (terminal No. 85).
Q: Is the harness wire in good condition?

YES : Replace the ECM. When the ECM is replaced, 

register the ID code. Refer to GROUP 42B, ID Code 
Registration Necessity Judgment Table <Vehicles 
with KOS> 

P.42B-11

 or GROUP 42C, ID Codes 

Registration Judgment Table <Vehicles with WCM> 

P.42C-9

. Then go to Step 9.

NO :  Repair it. Then go to Step 9.

1
2

AK203563

C-49 harness 
connector: 
component side

AC

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-570

STEP 9. Using scan tool MB991958, read the diagnostic 
trouble code (DTC).

CAUTION

To prevent damage to scan tool MB991958, always turn the 
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958 to the data link connector.
(2) Turn the ignition switch to the "ON" position.
(3) Erase the DTC.
(4) Drive the vehicle at a minimum speed of 30 km/h (19 mph).
(5) After completing the test drive, read the DTC. Turn the 

ignition switch to the "LOCK" (OFF) position.

Q: Is DTC P0830 set?

YES : The inspection is complete.
NO :  Retry the troubleshooting.

DTC P1231: Active Stability Control Plausibility

.

TECHNICAL DESCRIPTION

• Checks for an abnormal signal of active stability 

control (ASC) via the CAN communication.

.

DTC SET CONDITIONS

Check Condition

• Ignition switch is "ON" position.

Judgment Criterion

• A torque demand signal from the active stability 

control is not normal.

.

FAIL-SAFE AND BACKUP FUNCTION

• Torque requested by active stability control (ASC) 

is ignored.

.

TROUBLESHOOTING HINTS (The most 
likely causes for this code to be set are:)

• Active stability control system failed.
• ECM failed.

DIAGNOSIS

Required Special Tools:

• MB991958: Scan Tool (M.U.T.-III Sub Assembly)

• MB991824: V.C.I.
• MB991827: USB Cable
• MB991910: Main Harness A

AC608435

Data link connector

MB991827

MB991824

MB991910

AB

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-571

STEP 1. Using scan tool MB991958, read the diagnostic 
trouble code (DTC).

CAUTION

To prevent damage to scan tool MB991958, always turn the 
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958 to the data link connector.
(2) Turn the ignition switch to the "ON" position.
(3) Read the DTC.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC P1231 set?

YES : Go to Step 2. 
NO :  It can be assumed that this malfunction is intermittent. 

Refer to GROUP 00, How to Use 
Troubleshooting/Inspection Service Points − How to 

Cope with Intermittent Malfunctions 

P.00-15

.

STEP 2. Using scan tool MB991958, read the diagnostic 
trouble code (DTC).
(1) Turn the ignition switch to the "ON" position.
(2) After the DTC has been deleted, read the ASC-DTC.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the ASC-DTC set?

YES : Refer to GROUP 35C, Active Stability Control System 

− Diagnostic Trouble Code Chart 

P.35C-22

.

NO :  Replace the ECM. When the ECM is replaced, 

register the ID code. Refer to GROUP 42B, ID Code 
Registration Necessity Judgment Table <Vehicles 
with KOS> 

P.42B-11

 or GROUP 42C, ID Codes 

Registration Judgment Table <Vehicles with WCM> 

P.42C-9

.

AC608435

Data link connector

MB991827

MB991824

MB991910

AB

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-572

DTC P1232: Fail Safe System

.

TECHNICAL DESCRIPTION

• To judge whether fail-safe control can be per-

formed, check that power supply to the throttle 
actuator control motor circuit can be stopped by 
turning the throttle actuator control motor relay to 
OFF position momentarily.

.

DTC SET CONDITIONS

Check Condition

• Ignition switch is "ON" position.

Judgment Criterion

• Power supply to the throttle actuator control 

motor cannot be shut down (though power supply 
is stopped).

.

FAIL-SAFE AND BACKUP FUNCTION

• Microcomputer is reset.

.

TROUBLESHOOTING HINTS (The most 
likely causes for this code to be set are:)

• Throttle actuator control motor relay circuit failed.
• ECM failed.

DIAGNOSIS

Required Special Tools:

• MB991958: Scan Tool (M.U.T.-III Sub Assembly)

• MB991824: V.C.I.
• MB991827: USB Cable
• MB991910: Main Harness A

STEP 1. Using scan tool MB991958, read the diagnostic 
trouble code (DTC).

CAUTION

To prevent damage to scan tool MB991958, always turn the 
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958 to the data link connector.
(2) Turn the ignition switch to the "ON" position.
(3) Read the DTC.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the DTC P1232 set?

YES : Go to Step 2. 
NO :  It can be assumed that this malfunction is 

intermittent.Refer to GROUP 00, How to Use 
Troubleshooting/Inspection Service Points − How to 

Cope with Intermittent Malfunctions 

P.00-15

.

AC608435

Data link connector

MB991827

MB991824

MB991910

AB