Mitsubishi Galant 9G. Manual - part 935

 

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Mitsubishi Galant 9G. Manual - part 935

 

 

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-40

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-41

DIAGNOSTIC TROUBLE CODE PROCEDURES

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

.

TECHNICAL DESCRIPTION

• The PCM 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 PCM 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 
PCM 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)

• Not applicable

.

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-42

DTC SET CONDITIONS
Logic Flow Chart

Check Conditions

• Ignition switch is in "LOCK" (OFF) position.

• After two seconds pass from the time when the 

engine is stopped.

• Engine coolant temperature is higher than 0°C 

(32

°F).

Judgment 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.

.

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.

• PCM failed.

START

YES

YES

YES

NO

NO

NO

|BAROMETRIC PRESSURE  | MANIFOLD 

PRESSURE| > 9kPa (2.7in.Hg)

CONTINUOUS

FAILURE FOR 2secs

MALFUNCTION

END

GOOD

MONITORING

CONDITIONS

AK401533

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-43

DIAGNOSIS

Required Special Tools

• MB991958: Scan tool (MUT-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.13B-34

.

NO :  Go to Step 2.

AK303804AB

MB991910

DATA LINK
CONNECTOR

MB991824

MB991827

 

 

 

 

 

 

 

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