Mitsubishi Lancer Evolution X. Manual - part 260

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-105

DIAGNOSIS

Required Special Tool:

• MB991658: Test Harness

STEP 1. Check the heated oxygen sensor (rear).
(1) Disconnect heated oxygen sensor (rear) connector D-35 

and connect test harness special tool, MB991658, to the 
connector on the heated oxygen sensor (rear) side.

(2) Measure the resistance between heated oxygen sensor 

connector terminal No. 1 and terminal No. 2.

Standard value: 4.5 − 8.0 Ω [at 20° C (68° F)]

Q: Is the measured resistance between 4.5 and 8.0 Ω [at 

20° C (68° F)]?
YES : Go to Step 2.
NO :  Replace the heated oxygen sensor (rear). Then go to 

Step 3.

STEP 2. Check the trouble symptoms.
(1) Carry out a test drive with the drive cycle pattern. Refer to 

Diagnostic Function − OBD-II Drive Cycle − Pattern 2 

P.13A-9

.

(2) Check the diagnostic trouble code (DTC).
Q: Is DTC P0038 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 3.

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 3. 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 2 

P.13A-9

.

(2) Check the diagnostic trouble code (DTC).
Q: Is DTC P0038 set?

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

AK604492AB

MB991658

Heated oxygen
sensor component
side connector

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-106

DTC P0069: Abnormal Correlation Between Manifold Absolute Pressure Sensor And Barometric 
Pressure Sensor

.

TECHNICAL DESCRIPTION

• The ECM detects abnormality in the sensor by 

comparing the manifold absolute pressure sensor 
output with the barometric pressure sensor out-
put.

.

DESCRIPTIONS OF MONITOR METHODS

The ECM compares the manifold absolute pressure 

sensor output with the barometric pressure sen-
sor output while the engine control relay is in 
"ON" position after the ignition switch is in 
"LOCK" (OFF) position. When the difference 
exceeds the specified value between them, the 
ECM determines whether the manifold absolute 
pressure sensor / the barometric pressure sensor 
has malfunction 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)

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

.

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-107

DTC SET CONDITIONS
Logic Flow Chart

Check Conditions

• Ignition switch is in "LOCK" (OFF) position.
• After 2 seconds pass from the time when the 

engine is stopped.

• Engine coolant temperature is higher than 0° C 

(32° F).

Judgement Criterion

• Difference between manifold absolute pressure 

sensor output and barometric pressure sensor 
output is more than 9 kPa (2.7 in.Hg) for 2 sec-
onds.

.

FAIL-SAFE AND BACKUP FUNCTION

• None

.

OBD-II DRIVE CYCLE PATTERN

None.

.

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

• Manifold absolute pressure sensor failed.
• Barometric pressure sensor failed.
• ECM failed.

No

No

No

|Barometric pressure-

manifold pressure| > 9kPa

(2.7 in. Hg)

Malfunction

End

Good

AK704095

Start

Yes

Yes

Yes

Continuous
failure for 2secs

Monitoring
conditions

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI)

13A-108

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) Set scan tool MB991958, read the DTC.
(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the diagnostic trouble code other than P0069 set?

YES : Refer to, Diagnostic Trouble Code Chart 

P.13A-48

.

NO :  Go to Step 2.

AC608435

Data link connector

MB991827

MB991824

MB991910

AB