Mitsubishi Galant. Manual — part 105

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L>

13A-101

STEP 3. Check the sensor supply voltage at throttle
position sensor harness side connector B-05.
(1) Disconnect the connector B-05 and measure at the harness

side.

(2) Turn the ignition switch to the "ON" position.
(3) Measure the voltage between terminal 4 and ground.

•

Voltage should be between 4.8 and 5.2 volts.

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

Q: Is the voltage normal?

YES : Go to Step 5.
NO : Go to Step 4.

STEP 4. Check connector C-40 at PCM for damage.
Q: Is the connector in good condition?

YES : Replace the PCM. Then go to Step 11.
NO : Repair or replace it. Refer to GROUP 00E, Harness

Connector Inspection (

P.00E-2

). Then go to Step 11.

STEP 5. Check the continuity at throttle position sensor
harness side connector B-05.
(1) Disconnect the connector B-05 and measure at the harness

side.

(2) Measure the continuity between terminal 1 and ground.

•

Should be less than 2 ohm.

Q: Is the continuity normal?

YES : Go to Step 8.
NO : Go to Step 6.

STEP 6. Check connector C-40 at PCM for damage.
Q: Is the connector in good condition?

YES : Go to Step 7.
NO : Repair or replace it. Refer to GROUP 00E, Harness

Connector Inspection (

P.00E-2

). Then go to Step 11.

AK000236

B-05 HARNESS
SIDE CONNECTOR

1

2

3

4

AE

AK000280

CONNECTOR : C-40

PCM

AV

AK000237

B-05 HARNESS
SIDE CONNECTOR

1

2

3

4

AD

AK000280

CONNECTOR : C-40

PCM

AV

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L>

13A-102

STEP 7. Check for open circuit and harness damage
between throttle position sensor connector B-05 terminal 1
and PCM connector C-40 terminal 57.
Q: Is the harness wire in good condition?

YES : Replace the PCM. Then go to Step 11.
NO : Repair it. Then go to Step 11.

STEP 8. Check the throttle position sensor.
(1) Disconnect the connector B-05.
(2) Measure the resistance between throttle position sensor

side connector terminal 1 and 4.

Standard value: 3.5

−−−−

6.5 k

Ω

Ω

Ω

Ω

(3) Measure resistance between the throttle position sensor

side connector terminal 1 and 3.

(4) Move the throttle valve from the idle position to the full-open

position.

•

Resistance should change smoothly in proportion to the
opening angle of the throttle valve.

Q: Is the resistance normal?

YES : Go to Step 9.
NO : Replace the throttle position sensor.(Refer to

P.13A-

452

, Throttle Body.) Then go to Step 11.

ACX02472

CONNECTOR : B-05

THROTTLE
POSITION
SENSOR

AG

AK000280

CONNECTOR : C-40

PCM

AV

ACX02472

CONNECTOR : B-05

THROTTLE
POSITION
SENSOR

AG

AK000320

1 2 3 4

THROTTLE POSITION
SENSOR SIDE
CONNECTOR

AB

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L>

13A-103

STEP 9. Check connector C-40, C-41 at PCM for damage.
Q: Is the connector in good condition?

YES : Go to Step 10.
NO : Repair or replace it. Refer to GROUP 00E, Harness

Connector Inspection (

P.00E-2

). Then go to Step 11.

STEP 10. Using scan tool MB991502, check data list item
14: Throttle Position 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) Turn the ignition switch to the "ON" position.
(3) Set scan tool MB991502 to the data reading mode for item

14, Throttle Position Sensor.

•

With the throttle valve in the idle position, voltage should
be between 0.535 and 0.735 volts.

•

With the throttle valve in the full-open position, voltage
should be between 4.5 and 5.5 volts.

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

Q: Is the sensor operating properly?

YES : It can be assumed that this malfunction is intermittent.

Refer to GROUP 00, How to Use Troubleshooting/
Inspection Service Points(

P.00-8

).

NO : Replace the PCM. Then go to Step 11.

STEP 11. Test the OBD-II drive cycle.
(1) Carry out a test drive with the drive cycle pattern. Refer to,

Procedure 6

−

Other Monitor(

P.13A-5

).

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

Q: Is the DTC P0123 is output?

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

DTC P0128: Coolant Thermostat Malfunction

TECHNICAL DESCRIPTION

•

The PCM checks the time for the engine coolant
temperature to reach the judgment temperature.

DTC SET CONDITIONS

Check Conditions

•

Engine coolant temperature is between -10

°

C

(14

°

F) and 82

°

C (180

°

F) when the engine is

started.

AK000280

CONNECTORS : C-40, C-41

C-41

C-40

PCM

AX

AC003081 AB

16 PIN

MB991502

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI) <2.4L>

13A-104

•

The engine coolant temperature

−

intake air

temperature is 5

°

C (48

°

F) or less when the

engine is started.

•

The intake air temperature when the engine is
started

−

intake air temperature is 2

°

C (36

°

F) or

less.

•

The volume air flow sensors output frequency is
in the low frequency (50-100Hz or less) state for
400 seconds or less.

Judgment Criteria

•

The time for the engine coolant temperature to
rise to 82

°

C (180

°

F) takes longer than the

specified time *.

*: Approximately 11 to 23 minutes when the

engine coolant temperature at start is 20

°

C

(68

°

F) or more.

Approximately 12 to 60 minutes when the engine

coolant temperature at start is 20

°

C (68

°

F)

or less.

•

Only one monitor during one drive cycle.

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

•

The thermostat is faulty

•

PCM failed.

DIAGNOSIS

STEP 1. Check the cooling system.
Refer to GROUP 14, Engine Cooling Diagnosis (

P.14-2

).

Q: Is the cooling system normal?

YES : Replace the PCM. Then check that the DTC P0128

does not reset.

NO : Repair it. Then check that the DTC P0128 does not

reset.