Mitsubishi Evolution X. Manual - part 261

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI)

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NOTE: *1: Minimum value: The test fails if test value is less than this value.
NOTE: *2: Maximum value: The test fails if test value is greater than this value.
NOTE: When not finishing the monitor of the driving cycle for the request of On-Board Monitoring Test
Request, the ECM outputs the stored latest monitor test result.
NOTE: When the monitored test results are erased by the battery disconnection and so on, the ECM outputs
the values in hexadecimal of "0000" or "FFFF", otherwise it outputs abnormal values and so on. In case of
this, the ECU outputs are handled as invalid-values. When the first monitor (Readiness Status) is completed
after this, the ECM outputs the valid-values.
NOTE: "Test Limit Type & Component ID byte" output from the ECM is given in hexadecimal of "00" or "80".
"00" means the maximum value and "80" means the minimum value.

Mis-Fire Cylinder 2 Data
EWMA Misfire Counts For
Last 10 Driving Cycles

ECM monitors angular
acceleration of crankshaft
and detect misfire. EWMA
(Exponential Weighted
Moving Average) misfire
counts for last 10 driving
cycles.

× 1 count

Mis-Fire Cylinder 2 Data
Misfire Counts For
Last/Current Driving Cycle

ECM monitors angular
acceleration of crankshaft
and detect misfire. Misfire
counts for last/current driving
cycle.

× 1 count

Mis-Fire Cylinder 3 Data
EWMA Misfire Counts For
Last 10 Driving Cycles.

ECM monitors angular
acceleration of crankshaft
and detect misfire. EWMA
(Exponential Weighted
Moving Average) misfire
counts for last 10 driving
cycles.

× 1 count

Mis-Fire Cylinder 3 Data
Misfire Counts For
Last/Current Driving Cycle

ECM monitors angular
acceleration of crankshaft
and detect misfire. Misfire
counts for last/current driving
cycle.

× 1 count

Mis-Fire Cylinder 4 Data
EWMA Misfire Counts For
Last 10 Driving Cycles

ECM monitors angular
acceleration of crankshaft
and detect misfire. EWMA
(Exponential Weighted
Moving Average) misfire
counts for last 10 driving
cycles.

× 1 count

Mis-Fire Cylinder 4 Data
Misfire Counts For
Last/Current Driving Cycle

ECM monitors angular
acceleration of crankshaft
and detect misfire. Misfire
counts for last/current driving
cycle.

× 1 count

ON-BOARD
DIAGNOSTIC
MONITOR ID

STANDARDIZED /
MANUFACTURER
DEFIND TEST ID

MONITORING ITEM

SIMPLE TECHNICAL DESCRIPTION

CONVERSION
COEFFICIENT IN USING
GENERAL SCAN TOOL

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI)

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DIAGNOSTIC BY DIAGNOSTIC TEST MODE II
(INCREASED SENSITIVITY)

Required Special Tools:

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

• MB991824: V.C.I.

• MB991827: USB Cable

• MB991910: Main Harness A

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.
NOTE: When mode II is selected with MB991958, the Malfunc-
tion Indicator Lamp (SERVICE ENGINE SOON or Check
Engine Lamp) will light when the engine control module (ECM)
first detects the trouble (Note that this is only for emis-
sion-related trouble). At the same time, the relevant diagnostic
trouble codes will be registered. In respect to the comprehen-
sive component electrical faults (opens/shorts), the time for the
diagnostic trouble code to be registered after the fault occur-
rence is four seconds

→

one second. Therefore, the confirma-

tion of the trouble symptom and the confirmation after
completing repairs can be reduced. To return to the normal
mode I after mode II has been selected once, the ignition
switch must be turned "OFF" once or mode I must be rese-
lected with the scan tool MB991958. The diagnostic trouble
code, system readiness test status and freeze frame data, etc.,
will be erased when mode I is returned to, so record these
before returning to mode I.
1. Connect scan tool MB991958 to the data link connector.
2. Turn the ignition switch to the "ON" position.
3. Change the diagnostic test mode of the engine control

module to DIAGNOSTIC TEST MODE II (INCREASED
SENSITIVITY).

4. Road test the vehicle.
5. Read the diagnostic trouble code and repair the

malfunctioning part.

6. Turn the ignition switch to the "LOCK" (OFF) position.
7. Disconnect scan tool MB991958 from the data link

connector.

AC608435

Data link connector

MB991827

MB991824

MB991910

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI)

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ON-BOARD DIAGNOSTICS

The engine control module (ECM) monitors the
input/output signals (some signals all the time and
others under specified conditions) of the ECM. When
a malfunction continues for a specified time or longer
after the irregular signal is initially monitored, the
ECM judges that a malfunction has occurred. After
the ECM first detects a malfunction, a diagnostic
trouble code is recorded when the engine is restarted
and the same malfunction is re-detected. However,
for items marked with a "*", a diagnostic trouble code
is recorded on the first detection of the malfunction.
There are 134 diagnostic items. The diagnostic
results can be read out with a scan tool. Since mem-
orization of the diagnostic trouble codes is backed up
directly by the battery, the diagnostic results are
memorized even if the ignition key is turned off. The
diagnostic trouble codes will, however, be erased
when the battery terminal or the ECM connector is
disconnected. In addition, the diagnostic trouble
code can also be erased by turning the ignition
switch to ON and sending the diagnostic trouble
code erase signal from scan tool MB991958 to the
ECM.

NOTE: If the sensor connector is disconnected with
the ignition switch turned on, the diagnostic trouble
code is memorized. In this case, send the diagnostic
trouble code erase signal to the ECM in order to
erase the diagnostic memory. The 134 diagnostic
items are all indicated sequentially from the smallest
code number. The ECM records the engine operat-
ing condition when the diagnostic trouble code is set.
This data is called "Freeze-frame" data. This data
can be read by using the scan tool, and can then be
used in simulation tests for troubleshooting. Data
items are as follows:
NOTE: If the ECM detects multiple malfunctions, the
ECM stores the "Freeze-frame" data for only the first
item that was detected. However, if the ECM detects
a misfire or a fuel system malfunction, the ECM
stores the data by giving priority to the misfire or fuel
system malfunction, regardless of the order in which
the malfunction was detected.
NOTE: As for Diagnostic trouble code P1603,
"Freeze-frame" data is not memorized.

Freeze Frame Data for M.U.T.-III

NOTE: *: The total time, in which the failure determination is carried out while the ignition switch is in the ON
position.
Freeze Frame Data for M.U.T.-III

ITEM NO. M.U.T.-III SCAN TOOL

DISPLAY

DATA ITEM

UNIT or STATE

Odometer

Ignition cycle (Warm
up cycle)

Ignition cycle (Warm up cycle)

−

Accumulated minute

Accumulated minute*

min

ITEM NO. M.U.T.-III SCAN TOOL

DISPLAY

DATA ITEM

UNIT or STATE

Airflow sensor

Mass airflow sensor

g/s

TP sensor (main)

Throttle position sensor (main)

Barometric pressure
sensor

Barometric pressure sensor

kPa or in.Hg

Relative TP sensor

Relative throttle position sensor

TP sensor (sub)

Throttle position sensor (sub)

APP sensor (main)

Accelerator pedal position sensor (main) %

APP sensor (sub)

Accelerator pedal position sensor (sub)

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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NOTE: *Data items are displayed on M.U.T.-III display, but the in-line 4 engine is not applicable and its data is
displayed as "N/A" or "****".

Fuel system status
(bank 1)

Fuel system status

• Open loop
• Closed loop
• Open loop-drive

condition

• Open loop-DTC set
• Closed loop-O2 (rear)

failed

C1*

Fuel system status
(bank 2)

Fuel system status (bank 2)

N/A

Calculated load value

ECT sensor

Engine coolant temperature sensor

° C or ° F

Short term fuel trim
(bank 1)

Short term fuel trim

C5*

Short term fuel trim
(bank 3)

Short term fuel trim (bank 3)

****

Long term fuel trim
(bank 1)

Long term fuel trim

C7*

Long term fuel trim
(bank 3)

Long term fuel trim (bank 3)

****

MAP sensor

Manifold absolute pressure sensor

kPa or in.Hg

Crankshaft position
sensor

Crankshaft position sensor

r/min

Vehicle speed

km/h or mph

Spark advance

deg

Intake air temperature
sensor

Intake air temperature sensor

° C or ° F

Time since engine
running

Time since engine running

sec

EVAP. emission purge
SOL. duty

Evaporative emission purge solenoid
duty

Fuel level gauge

Power supply voltage

Absolute load value

Target equivalence
ratio

Target equivalence ratio

Intake air temperature
sensor

Intake air temperature sensor

° F

Throttle actuator

Throttle actuator control motor

ITEM NO. M.U.T.-III SCAN TOOL

DISPLAY

DATA ITEM

UNIT or STATE

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