Mitsubishi Galant (2004+). Manual - part 1086

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-37

NOTE: Do not replace the powertrain control module (PCM) until a through terminal check reveals there are
no short/open circuits.
NOTE: Check that the PCM ground circuit is normal before checking for the cause of the problem.
NOTE: After the PCM detects a malfunction, a diagnostic trouble code is recorded the next time the engine is
started and the same malfunction is re-detected. However, for items marked with a "*", the diagnostic trouble
code is recorded on the first detection of the malfunction.
NOTE: Sensor 1 indicates the sensor mounted at a position closest to the engine, and sensor 2 indicates the
sensor mounted at the position second closest to the engine.
NOTE: Bank 1 indicates the right bank side cylinder, and Bank 2 indicates the left bank side cylinder.

SYMPTOM CHART

M1131151500726

CAUTION

During diagnosis, a DTC associated with other
system may be set when the ignition switch is
turned on with connector(s) disconnected. On
completion, confirm all systems for DTC(s). If
DTC(s) are set, erase them all.

CAUTION

Disconnecting the battery cables or removing the
combination meter will erase the learned value of
the fuel gauge. To recover the learned value,
input a vehicle speed (by actually driving the
vehicle or inputting a simulated vehicle speed),
and stop the vehicle. This will complete the learn-
ing process.

NOTE: Check that the PCM ground circuit is normal
before checking for the cause of the problem.

U1102

ABS

−ECU time−out

P.13B-951

U1108*

Combination meter time

−out

P.13B-955

U1110

A/C

−ECU time−out

P.13B-960

DTC

DIAGNOSTIC ITEM

REFERENCE
PAGE

TROUBLE SYMPTOMS

INSPECTION
PROCEDURE

REFERENCE PAGE

Communication
with scan tool is
impossible

Communication with all systems is not possible

P.13B-965

Communication with PCM only is not possible

P.13B-968

Malfunction
Indicator Lamp
(SERVICE
ENGINE SOON
or Check
Engine Lamp)
and related
parts

The Malfunction Indicator Lamp (SERVICE ENGINE
SOON or Check Engine Lamp) does not illuminate
right after the ignition switch is turned to the "ON"
position

P.13B-971

The Malfunction Indicator Lamp (SERVICE ENGINE
SOON or Check Engine Lamp) remains illuminated
and never goes out

P.13B-972

Starting

Cranks, won't start

P.13B-974

Starts up and dies

P.13B-981

Hard starting

P.13B-988

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-38

PROBLEM SYMPTOMS TABLE (FOR YOUR INFORMATION)

Idling stability
(improper
idling)

Unstable idle (rough idle, hunting)

P.13B-995

Idle speed is high (improper idle speed)

P.13B-999

Idle speed is low (improper idle speed)

P.13B-1001

Idling stability
(engine stalls)

When the engine is cold, it stalls at idle (die out)

P.13B-1002

When the engine is hot, it stalls at idle (die out)

P.13B-1006

The engine stalls when accelerating (pass out)

P.13B-1010

The engine stalls when decelerating

P.13B-1011

Driving

Hesitation, sag or stumble

Acceleration shock

Deceleration shock

Poor acceleration

Surge

Knocking

Dieseling (Run-on)

Too high CO and HC concentration when idling

P.13B-1029

IM240 test
failure

Transient, mass emission tailpipe test failure

P.13B-1032

Purge flow test of the evaporative emission canister
failure

P.13B-1039

Pressure test of the evaporative system failure

P.13B-1040

Generator output voltage is low (approximately 12.3 volts)

P.13B-1041

Fans (radiator fan, A/C condenser fan) are inoperative

P.13B-1046

Power supply system and ignition switch-IG system

P.13B-1050

Fuel pump system

P.13B-1061

Ignition switch-ST system and transmission range switch system

P.13B-1074

Ignition circuit system

P.13B-1079

A/C system

P.13B-1089

TROUBLE SYMPTOMS

INSPECTION
PROCEDURE

REFERENCE PAGE

ITEMS

SYMPTOM

At starting

Won't start

The starter cranks the engine, but there is no combustion within the
cylinders, and the engine won't start.

Starts up and
dies

The engine starts, but then engine soon stalls.

Hard starting

Engine starts after cranking a while.

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-39

Idling stability

Hunting

Engine speed doesn't remain constant; changes at idle.

Rough idle

Usually, a judgement can be based upon the movement of the
tachometer pointer, and the vibration transmitted to the steering wheel,
shift lever, body, etc.

Incorrect idle
speed

The engine doesn't idle at the correct speed.

Engine stall (die
out)

The engine stalls when the foot is taken from the accelerator pedal,
regardless of whether the vehicle is moving or not.

Engine stall
(pass out)

The engine stalls when the accelerator pedal is depressed.

At driving

Hesitation Sag

"Hesitation" is the delay in
response of the vehicle speed
(engine speed). This occurs when
the accelerator is depressed in
order to accelerate from the speed
at which the vehicle is now
traveling, or a temporary drop in
vehicle speed (engine speed)
during such acceleration.
Serious hesitation is called "sag".

Poor
acceleration

Poor acceleration is inability to obtain an acceleration corresponding to
the degree of throttle opening, even though acceleration is smooth.
Also the inability to reach maximum speed.

Stumble

Engine speed increase is delayed
when the accelerator pedal is
initially depressed for acceleration.

Shock

The feeling of a comparatively large impact or vibration when the
engine is accelerated or decelerated.

Surge

This is slight acceleration and deceleration feel usually felt during
steady, light throttle cruise. Most notable under light loads.

Knocking

A sharp sound during driving, which sounds like a hammer striking the
cylinder walls. It makes poor driveability.

At stopped

Run on
("Dieseling")

The condition in which the engine continues to run after the ignition
switch is turned to the "LOCK" (OFF) position. Also called "dieseling".

ITEMS

SYMPTOM

AKX01361

VEHICLE
SPEED

TIME

NORMAL

HESITATION

SAG

INITIAL
ACCELE-
RATOR
PEDAL
DEPRE-
SSION

AKX01361AB

AKX01362

VEHICLE
SPEED

TIME

NORMAL

STUMBLE

INITIAL
ACCEL-
ERATOR
PEDAL
DEP-
RESSION

IDLING

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-40

DIAGNOSTIC TROUBLE CODE PROCEDURES

DTC P0101: Mass Airflow Circuit Range/Performance Problem

CAUTION

If DTC P0101 has been set, TCL related DTC
U1120 is also set. After P0101 has been diag-
nosed, don't forget to erase DTC U1120.

RED

RED-

WHITE

RED-

WHITE

RED-

WHITE

AK302832

B-10

B-17X

MFI
RELAY

BATTERY

MASS AIRFLOW
SENSOR

Mass Airflow Sensor Circuit

3 4

WHITE-GREEN

BLA

POWERTRAIN CONTROL
MODULE (PCM)

108

B-22

B-21

HEAT
SENSITIZING
RESISTANCE

100

93 94 95

96 97 98

101 102 103 104

105 106 107 108

109 110 111 112 113

53 54 55 56

58 59 60 61 62

64 65 66 67 68 69

71 72 73 74 75

77 78 79 80 81 82

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