Content .. 1078 1079 1080 1081 ..

Mitsubishi Galant (2004+). Manual - part 1080

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-13

HOW TO DIAGNOSE THE CAN BUS LINES

Required Special Tools:

• MB991958: Scan Tool (MUT-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.
1. Connect scan tool MB991958 to the data link connector.
2. Turn the ignition switch to the "ON" position.
3. Select "CAN bus diagnosis" from the start-up screen.
4. When the vehicle information is displayed, confirm that it

matches the vehicle whose CAN bus lines will be
diagnosed.

• If they matches, go to step 8.

• If not, go to step 5.

5. Select the "view vehicle information" button.
6. Enter the vehicle information and select the "OK" button.
7. When the vehicle information is displayed, confirm again

that it matches the vehicle whose CAN bus lines will be
diagnosed.

• If they matches, go to step 8.

• If not, go to step 5.

8. Select the "OK" button.
9. When the optional equipment screen is displayed, choose

the one which the vehicle is fitted with, and then select the
"OK" button.

PROVISIONAL DTCs [MUT-III OBD-II Test Mode -
Results (Mode 7)]

The scan tool MB991958 (MUT-III sub assembly) will display
the Provisional DTCs reported by PCM if the PCM detects
some malfunction for "Misfire", "Fuel System" and "Compre-
hensive" monitoring during a SINGLE Driving Cycle. The
intended use of this data is to assist the technician after a vehi-
cle repair, and after clearing diagnostic information, by report-
ing test result after a SINGLE Driving Cycle. Note that the test
results reported by this mode do not necessarily indicate a
faulty component/system. If test results indicate a failure after
ADDITIONAL (consecutive) driving, then the Malfunction Indi-
cator Lamp (SERVICE ENGINE SOON or Check Engine
Lamp) will be illuminated and a DTC will set.

AC206894

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-14

MODE 6 REFERENCE TABLE

The powertrain control module (PCM) monitors the condition of emission control system.
By selecting MODE 6 using scan tool, Test Result and Limit Value (minimum) *1 or (maximum) *2 about the
main items of emission control system which PCM monitors can be confirmed. The value at the last monitor-
ing is output by PCM as a test result.

TEST
ID

MONITORING
ITEM

SIMPLE TECHNICAL
DESCRIPTION

INDICATION OF SCAN
TOOL

CONVERSION
COEFFICIENT IN
USING
GENERAL SCAN
TOOL

Catalyst
monitor (Bank
1)

PCM monitors the deterioration of
catalyst at right bank side by the
output frequency ratio between
right bank heated oxygen sensor
(front) and right bank heated
oxygen sensor (rear).

Catalyst Frequency
Ratio Bank 1
Test Result and Limit
Value (max.)

× 0.0039

Catalyst
monitor (Bank
2)

PCM monitors the deterioration of
catalyst at left bank side by the
output frequency ratio between left
bank heated oxygen sensor (front)
and left bank heated oxygen sensor
(rear).

Catalyst Frequency
Ratio Bank 2
Test Result and Limit
Value (max.)

× 0.0039

EGR monitor

PCM monitors the operation of
EGR system by the pressure
difference of intake manifold
between before and after
introduction of EGR using the
manifold absolute pressure sensor.

EGR Monitor Pressure
Value
Test Result and Limit
Value (min.) kPa

× 0.43 kPa

Evaporation
leak monitor
(Small leak)

After PCM vacuumizes the fuel tank
and the fuel line and then the
specified time is passed, PCM
monitors the leak of fuel
evaporation gas through the fuel
tank differential pressure sensor to
check the reduction of vacuum in
the fuel tank.

EVAP Leak Mon. 1 mm
Pressure Value
Test Result and Limit
Value (max.) kPa

× 0.032 kPa

Evaporation
leak monitor
(Gross leak)

PCM monitors the leak of fuel
evaporation gas by checking
whether the pressure can be
reduced (the amount of pressure
reduction) using the fuel tank
differential pressure sensor after
sealing the fuel tank and the fuel
line.

EVAP Leak Mon. Gross
Pressure Value
Test Result and Limit
Value (min.) kPa

× 0.032 kPa

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-15

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.

Evaporation
leak monitor
(Very small
leak)

EVAP Leak Mon. 0.5
mm Pressure Value
Test Result and Limit
Value (max.) kPa

× 0.032 kPa

Heated oxygen
sensor monitor
(Rich/Lean
Switching)
(Bank 1 Sensor
1)

PCM monitors the deteriorated
condition of the heated oxygen
sensor by checking the lean/rich
switching frequency of the heated
oxygen sensor.

HO2S B1 SENSOR 1
Rich/Lean Switching
Count
Test Result and Limit
Value (min.)

×1 time

Heated oxygen
sensor monitor
(Rich/Lean
Switching)
(Bank 2 Sensor
1)

PCM monitors the deteriorated
condition of the heated oxygen
sensor by checking the lean/rich
Switching frequency of the heater
oxygen sensor.

HO2S B2 SENSOR 1
Rich/Lean Switching
Count
Test Result and Limit
Value (min.)

×1 time

Heated oxygen
sensor monitor
(Voltage) (Bank
1 Sensor 2)

PCM checks the output voltage of
the heated oxygen sensor (rear) in
order to monitor whether the heated
oxygen sensor output is stuck.

HO2S B1 SENSOR2
Change in Volt
Test Result and Limit
Value (min.)

× 19.5mV

Heated oxygen
sensor monitor
(Voltage) (Bank
2 Sensor 2)

PCM checks the output voltage of
the heated oxygen sensor (rear) in
order to monitor whether the heated
oxygen sensor output is stuck.

HO2S B2 SENSOR 2
Change in Volt
Test Result and Limit
Value (min.)

× 19.5mV

TEST
ID

MONITORING
ITEM

SIMPLE TECHNICAL
DESCRIPTION

INDICATION OF SCAN
TOOL

CONVERSION
COEFFICIENT IN
USING
GENERAL SCAN
TOOL

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-16

DIAGNOSTIC BY DIAGNOSTIC TEST MODE II
(INCREASED SENSITIVITY)

Required Special Tools:

• MB991958: Scan tool (MUT-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 powertrain control module
(PCM) 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 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 powertrain 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.

AC305412

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

Content .. 1078 1079 1080 1081 ..