Mitsubishi Galant. Manual — part 117

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L>

13A-149

STEP 10. Check for harness damage between injector
connector and PCM connector.

a. Check the harness wire between injector connector B-22

terminal 2 and PCM connector C-39 terminal 1 when
checking No.1 cylinder.

b. Check the harness wire between injector connector B-21

terminal 2 and PCM connector C-39 terminal 9 when
checking No.2 cylinder.

c. Check the harness wire between injector connector B-19

terminal 2 and PCM connector C-39 terminal 24 when
checking No.3 cylinder.

d. Check the harness wire between injector connector B-17

terminal 2 and PCM connector C-39 terminal 2 when
checking No.4 cylinder.

Q: Is the harness wire in good condition?

YES : Go to Step 11.
NO : Repair it. Then go to Step 14.

STEP 11. Check the fuel pressure.
Refer to, Fuel Pressure Test(

P.13A-439

).

Q: Is the fuel pressure normal?

YES : Go to Step 12.
NO : Repair or replace it. Then go to Step 14.

STEP 12. Check for entry of foreign matter (water,
kerosene, etc.) into fuel.

Q: Are there any abnormalities?

YES : Go to Step 13.
NO : Replace the fuel. Then go to Step 14.

STEP 13. Replace the injector.
(1) Replace the injector.
(2) Carry out a test drive with the drive cycle pattern. Refer to,

Procedure 2

−

Fuel Trim Monitor(

P.13A-5

).

(3) Check the diagnostic trouble code (DTC).

Q: Is the DTC P0171 is output?

YES : Replace the PCM. Then go to Step 14.
NO : The inspection is complete.

AK000557 AB

B-21

B-19

B-17

B-22

CONNECTORS:B-17,B-19,B-21,B-22

AK000280

CONNECTOR : C-39

PCM

AW

AK000557 AB

B-21

B-19

B-17

B-22

CONNECTORS:B-17,B-19,B-21,B-22

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L>

13A-150

STEP 14. Test the OBD-II drive cycle.
(1) Carry out a test drive with the drive cycle pattern. Refer to,

Procedure 2

−

Fuel Trim Monitor(

P.13A-5

).

(2) Check the diagnostic trouble code (DTC).

Q: Is the DTC P0171 is output?

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

DTC P0172: System too Rich

Fuel Trim Circuit

•

Refer to, P0201_P0204 Injector Circuit (

P.13A-

154

).

CIRCUIT OPERATION

•

Refer to, P0201_P0204 Injector Circuit (

P.13A-

154

).

TECHNICAL DESCRIPTION

•

If a malfunction occurs in the fuel system, the fuel
trim value becomes too small.

•

The PCM checks whether the fuel trim value is
within a specified range.

DTC SET CONDITIONS

Check Conditions

•

Engine coolant temperature is lower than
approximately 100

°

C (212

°

F) when the engine

is started.

•

Intake air temperature is lower than 60

°

C (140

°

F) when the engine is started.

•

Under the closed loop air/fuel ratio control.

•

Intake air temperature is higher than -10

°

C (14

°

F).

•

Barometric pressure is higher than 76kPa (11
psi).

•

Volume air flow sensor output frequency is 88 Hz
or more.

Judgment Criteria

•

Long-term fuel trim has continued to be lower
than -12.5 for 2 seconds.

or

•

Short-term fuel trim has continued to be lower
than -10.0 for 2 seconds.

Check Conditions

•

Engine coolant temperature is lower than
approximately 100

°

C (212

°

F) when the engine

is started.

•

Intake air temperature is lower than 60

°

C (140

°

F) when the engine is started.

•

Under the closed loop air/fuel ratio control.

•

Intake air temperature is higher than -10

°

C (14

°

F).

•

Barometric pressure is higher than 76kPa (11
psi).

•

Volume air flow sensor output frequency is 88 Hz
or less.

Judgment Criteria

•

Long-term fuel trim has continued to be lower
than -12.5 for 2 seconds.

or

•

Short-term fuel trim has continued to be lower
than -15.0 for 2 seconds.

Check Conditions

•

Engine coolant temperature is higher than
approximately 100

°

C (212

°

F) when the engine

is started.

•

Intake air temperature is higher than 60

°

C (140

°

F) when the engine is started.

•

Under the closed loop air/fuel ratio control.

•

Intake air temperature is higher than -10

°

C (14

°

F).

•

Barometric pressure is higher than 76kPa (11
psi).

•

Volume air flow sensor output frequency is 88 Hz
or more.

Judgment Criteria

•

Long-term fuel trim has continued to be lower
than -12.5 for 2 seconds.

or

•

Short-term fuel trim has continued to be lower
than -10.0 for 2 seconds.

Check Conditions

•

Engine coolant temperature is higher than
approximately 100

°

C (212

°

F) when the engine

is started.

•

Intake air temperature is higher than 60

°

C (140

°

F) when the engine is started.

•

Under the closed loop air/fuel ratio control.

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L>

13A-151

•

Intake air temperature is higher than -10

°

C (14

°

F).

•

Barometric pressure is higher than 76kPa (11
psi).

•

Volume air flow sensor output frequency is 88 Hz
or less.

Judgment Criteria

•

Long-term fuel trim has continued to be lower
than -12.5 for 2 seconds.

or

•

Short-term fuel trim has continued to be lower
than -15.0 for 2 seconds.

Check Conditions

•

Under the closed loop air/fuel ratio control.

•

The heated oxygen sensor (front) is active.

Judgment Criteria

•

Long-term fuel trim has continued to be lower
than -12.5 for 2 seconds.

or

•

Short-term fuel trim has continued to be lower
than -25.0 for 2 seconds.

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

•

Volume air flow sensor failed.

•

Injector failed.

•

Incorrect fuel pressure

•

Heated oxygen sensor failed.

•

Engine coolant temperature sensor failed.

•

Intake air temperature sensor failed.

•

Barometric pressure sensor failed.

•

Exhaust leak.

•

Use of incorrect or contaminated fuel.

•

PCM failed.

DIAGNOSIS

Required Special Tools
MB991502: Scan Tool (MUT-II)

STEP 1. Using scan tool MB991502, check data list item 12:
Volume Air Flow Sensor.

CAUTION

To prevent damage to scan tool MB991502, always turn the
ignition switch to the "LOCK"(OFF) position before
connecting or disconnecting scan tool MB991502.
(1) Connect scan tool MB991502 to the data link connector.
(2) Start the engine and run at idle.
(3) Set scan tool MB991502 to the data reading mode for item

12, Volume Air Flow Sensor.

(4) Warm up the engine to normal operating temperature: 80

°

C to 96

°

C(176

°

F to 205

°

F).

•

When idling, between 25 and 51 Hz (between 2.5 and
5.0 g/s).

•

When 2,500 r/min, between 80 and 120 Hz (between
8.5 and 12.7 g/s).

(5) Turn the ignition switch to the "LOCK"(OFF) position.

Q: Is the sensor operating properly?

YES : Go to Step 2.
NO : Refer to, DTC P0101

−

Volume Air Flow Circuit

Range/Performance Problem(

P.13A-26

), DTC P0102

−

Volume Air Flow Circuit Low Input(

P.13A-32

), DTC

P0103 - Volume Air Flow Circuit High Input(

P.13A-

35

).

AC003081 AB

16 PIN

MB991502

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L>

13A-152

STEP 2. Using scan tool MB991502, check data list item 13:
Intake Air Temperature Sensor.
(1) Turn the ignition switch to the "ON" position.
(2) Set scan tool MB991502 to the data reading mode for item

13, Intake Air Temperature Sensor.

•

The intake air temperature and temperature shown with
the scan tool should approximately match.

(3) Turn the ignition switch to the "LOCK"(OFF) position.

Q: Is the sensor operating properly?

YES : Go to Step 3.
NO : Refer to, DTC P0111

−

Intake Air Temperature Circuit

Range/Performance Problem(

P.13A-57

).

STEP 3. Using scan tool MB991502, check data list item 21:
Engine Coolant Temperature Sensor.
(1) Turn the ignition switch to the "ON" position.
(2) Set scan tool MB991502 to the data reading mode for item

21, Engine Coolant Temperature Sensor.

•

The engine coolant temperature and temperature
shown with the scan tool should approximately match.

(3) Turn the ignition switch to the "LOCK"(OFF) position.

Q: Is the sensor operating properly?

YES : Go to Step 4.
NO : Refer to, DTC P0115

−

Engine Coolant Temperature

Circuit High Input(

P.13A-66

), DTC P0116

−

Engine

Coolant Temperature Circuit Range/Performance
Problem(

P.13A-74

), DTC P0117

−

Engine Coolant

Temperature Circuit Low Input(

P.13A-79

).

STEP 4. Using scan tool MB991502, check data list item 25:
Barometric Pressure Sensor.
(1) Turn the ignition switch to the "ON" position.
(2) Set scan tool MB991502 to the data reading mode for item

25, Barometric Pressure Sensor.

•

When altitude is 0 m(0 foot), 101 kPa.

•

When altitude is 600 m(1,969 feet), 95 kPa.

•

When altitude is 1,200 m(3,937 feet), 88 kPa.

•

When altitude is 1,800 m(5,906 feet), 81 kPa.

(3) Turn the ignition switch to the "LOCK"(OFF) position.

Q: Is the sensor operating properly?

YES : Go to Step 5.
NO : Refer to, DTC P0107

−

Barometric Pressure Circuit

Low Input(

P.13A-41

), DTC P0108

−

Barometric

Pressure Circuit High Input(

P.13A-50

).

AC003081 AB

16 PIN

MB991502

AC003081 AB

16 PIN

MB991502

AC003081 AB

16 PIN

MB991502