Mitsubishi Lancer Evolution X. Manual - part 386

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-609

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) After the DTC has been deleted, read the DTC again.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the diagnostic trouble code other than P1507 set?

YES : Refer to Diagnostic Trouble Code Chart 

P.13A-48

.

NO :  Go to Step 2.

STEP 2. Check the intake system vacuum leak.
Q: Are there any abnormalities?

YES : Repair or replace it. Then go to Step 4.
NO :  Go to Step 3.

STEP 3. Replace the throttle body assembly.
(1) Replace the throttle body assembly.
(2) Carry out a test drive with the drive cycle pattern. Refer to 

Diagnostic Function − OBD-II Drive Cycle − Pattern 19 

P.13A-9

.

(3) Check the diagnostic trouble code (DTC).
Q: Is DTC P1507 set?

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 4.

NO :  The inspection is complete.

AC608435

Data link connector

MB991827

MB991824

MB991910

AB

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-610

STEP 4. Test the OBD-II drive cycle.
(1) Carry out a test drive with the drive cycle pattern. Refer to 

Diagnostic Function − OBD-II Drive Cycle − Pattern 19 

P.13A-9

.

(2) Check the diagnostic trouble code (DTC).
Q: Is DTC P1507 set?

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

DTC P1590: TCM to ECM Communication Error in Torque Reduction Request

.

TECHNICAL DESCRIPTIONS OF 
MONITOR METHODS

The ECM checks whether the errors in data commu-
nications sent by the TCM exist or not.

.

MONITOR EXECUTION

Continuous

.

MONITOR EXECUTION CONDITIONS 
(Other monitor and Sensor)

Other Monitor (There is no temporary DTC stored 

in memory for the item monitored below)

• Not applicable

Sensor (The sensor below is determined to be 

normal)

• Not applicable

.

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-611

DTC SET CONDITIONS
Logic Flow Chart

Check Condition

• Ignition switch is "ON" position.

Judgment Criterion

• ECM detects an error in communication between 

ECM and TCM.

.

FAIL-SAFE AND BACKUP FUNCTION

• Engine output is restricted.

.

OBD-II DRIVE CYCLE PATTERN

• None.

.

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

• CAN line harness damage or connector damage.
• ECM failed.

AK604369

Start

Yes

Yes

Yes

No

No

No

Continuous failure

for specified time

Malfunction

End

Good

Monitoring
conditions

Communication status

fails

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-612

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, diagnose CAN bus 
line.

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) Diagnose CAN bus line.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the CAN bus line normal?

YES : Go to Step 2 . 
NO :  Repair the CAN bus line. Refer to GROUP 54C, Can 

Bus Diagnostics Table 

P.54C-15

.

STEP 2. Using scan tool MB991958, read the diagnostic 
trouble code (DTC).
(1) Turn the ignition switch to the "ON" position.
(2) Read the DTC.
(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is DTC P1590 set?

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

.

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