Mitsubishi Lancer Evolution X. Manual - part 385

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-605

DTC SET CONDITIONS

Logic Flow Chart

.

Check Conditions

• Under the closed loop idle speed control.
• The engine coolant temperature is between 7° C 

(45° F) and 41° C (106° F).

• Battery positive voltage is higher than 10 volts.
• Barometric pressure is higher than 76 kPa (22.4 

in.Hg).

• Intake air temperature is higher than −10° C 

(14° F).

• More than 3 seconds have elapsed from the pre-

vious monitoring.

• Target air flow rate is 29 g/sec (24 L/sec) or more.

Judgment Criterion

• The actual idle speed is more than 100 r/min 

lower than the target idle speed for 10 seconds.

.

FAIL-SAFE AND BACKUP FUNCTION

• None

.

OBD-II DRIVE CYCLE PATTERN

Refer to Diagnostic Function − OBD-II Drive Cycle − 

Pattern 19 

P.13A-9

.

.

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

• Throttle valve area is dirty.
• Throttle body assembly failed.
• ECM failed.

Good

Malfunction

Calculate    Ne

End

No

No

No

AK704413

 Ne < -100 r/min

or > 200 r/min

Have 10secs passed?

Ne = (actual-Ne) - (target-Ne)

Ne:  engine speed

Start

Yes

Yes

Yes

Monitoring
conditions

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-606

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 P1506 set?

YES : Refer to Diagnostic Trouble Code Chart 

P.13A-48

.

NO :  Go to Step 2.

STEP 2. Check the throttle body. (throttle valve area)
Q: Is the throttle valve area dirty?

YES : Perform cleaning. Refer to Throttle body (throttle 

valve area) cleaning 

P.13A-865

. 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 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 P1506 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-607

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 P1506 set?

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

DTC P1507: Idle Control System RPM Higher Than Expected at Low Temperature

.

TECHNICAL DESCRIPTION

• The amount of air taken in during idling is regu-

lated by the opening and closing of the throttle 
valve.

• The ECM checks the difference between the 

actual engine speed and the target engine speed.

.

DESCRIPTIONS OF MONITOR METHODS

Difference between actual and target idle speed is 

over the specified value.

.

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)

• Misfire monitor
• Fuel system monitor
• Vehicle speed signal monitor

Sensor (The sensor below is determined to be 

normal)

• Mass airflow sensor
• Engine coolant temperature sensor
• Intake air temperature sensor
• Barometric pressure sensor
• Throttle position sensor

.

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-608

DTC SET CONDITIONS

Logic Flow Chart

.

Check Conditions

• Under the closed loop idle speed control.
• Engine coolant temperature is between 7° C 

(45° F) and 41° C (106° F).

• Battery positive voltage is higher than 10 volts.
• Barometric pressure is higher than 76 kPa (22.4 

in.Hg).

• Intake air temperature is higher than −10° C 

(14° F).

• More than 3 seconds have elapsed from the pre-

vious monitoring.

• Target air flow rate is 0 g/sec (0 L/sec).

Judgement Criterion

• Actual idle speed has continued to be higher than 

the target idle speed by 200 r/min (300 r/min*) or 
more for 10 seconds.

*: Specs in parentheses are applicable if the max-

imum air temperature during the previous 
operation was more than 45° C (113° F).

.

FAIL-SAFE AND BACKUP FUNCTION

• None

.

OBD-II DRIVE CYCLE PATTERN

Refer to Diagnostic Function − OBD-II Drive Cycle − 

Pattern 19 

P.13A-9

.

.

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

• Intake system vacuum leak.
• ECM failed.
• Throttle body assembly failed.

Good

Malfunction

Calculate    Ne

End

No

No

No

AK704413

 Ne < -100 r/min

or > 200 r/min

Have 10secs passed?

Ne = (actual-Ne) - (target-Ne)

Ne:  engine speed

Start

Yes

Yes

Yes

Monitoring
conditions