Mitsubishi Galant 9G. Manual — part 1184

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-1036

DIAGNOSIS

Required Special Tools:

• MB991958: Scan Tool (MUT-III Sub Assembly)

• MB991824: V.C.I.

• MB991827: USB Cable

• MB991910: Main Harness A

STEP 1. Measure the battery positive voltage.
(1) Measure the battery positive voltage during cranking.

• The voltage is 8 volts or more.

Q: Does the voltage remain greater than 8 volts while the

engine is cranked?
YES : Go to Step 2.
NO : Refer to GROUP 54A, Battery

− Battery check

P.54A-5

.

STEP 2. 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) Read the DTC.
(4) Turn the ignition switch the "LOCK" (OFF) position.
Q: Is the DTC set?

YES : Refer to Diagnostic Trouble Code Chart

P.13B-34

.

NO : Go to Step 3.

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-1037

STEP 3. Using scan tool MB991958, check actuator test.
(1) Turn the ignition switch to the "ON" position.
(2) Check the following items in the actuator test. Refer to

Actuator Test Reference Table

P.13B-1152

.

a. Item 07: Fuel Pump.

(3) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the actuator operating properly?

YES : Go to Step 4.
NO : Repair or Replace. Then confirm that the malfunction

symptom is eliminated.

STEP 4. Using scan tool MB991958, check data list.
(1) Turn the ignition switch the "ON" position.
(2) Check the following items in the data list. Refer to Data List

Reference Table

P.13B-1137

.

a. Item 21: Engine Coolant Temperature Sensor.

(3) Turn the ignition switch the "LOCK" (OFF) position.
Q: Is the sensor operating properly?

YES : Go to Step 5.
NO : Repair or Replace. Then confirm that the malfunction

symptom is eliminated.

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

AC305412

AB

MB991910

DATA LINK

CONNECTOR

MB991824

MB991827

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-1038

STEP 5. Inspection of throttle body (throttle valve area) for
dirtiness.
Q: Is the throttle valve area dirty?

YES : Refer to On-vehicle service

− Clean the throttle valve

area

P.13B-1178

.

NO : Go to Step 6.

STEP 6. Check the ignition timing.
(1) Check the ignition timing at cranking.

Standard value: 5

° BTDC ± 3°

Q: Is the ignition timing normal?

YES : Go to Step 7.
NO : Check that the crankshaft position sensor and timing

belt cover are in the correct position. Then confirm
that the malfunction symptom is eliminated.

STEP 7. Check the left bank injector.
(1) Disconnect the left bank injector connector B-27, B-26,

B-30.

(2) Measure the resistance between each injector side

connector terminal No. 1 and No. 2.

Standard value: 10.5

− 13.5 ohms [at 20°C (68°F)]

Q: Is the measured resistance between 10.5 and 13.5 ohms

[at 20

°C (68°F)]?

YES : Go to Step 8.
NO : Replace the faulty injector. Then confirm that the

malfunction symptom is eliminated.

AK303075

M

1

2

CONNECTOR: B-26, B-27, B-30

B-30 (GR)

B-27 (GR)

B-26 (GR)

HARNESS CONNECTOR:
COMPONENT SIDE

AB

AK000559

2

1

INJECTOR SIDE
CONNECTOR

AB

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-1039

STEP 8. Check the right bank injector resistance at
intermediate connector B-32.
(1) Disconnect the intermediate connector B-32.

(2) Measure the resistance between each male connector side

terminal.

a. Measure the resistance between terminal No. 9 and No.

5 at No. 1 cylinder injector.

b. Measure the resistance between terminal No. 9 and No.

10 at No. 3 cylinder injector.

c. Measure the resistance between terminal No. 9 and No.

4 at No. 5 cylinder injector.

• Resistance should be between 10.5 and 13.5 ohms [at

20

°C (68°F)].

Q: Is the measured resistance between 10.5 and 13.5 ohms

[at 20

°C (68°F)]?

YES : Go to Step 11.
NO : Go to Step 9.

STEP 9. Check the right bank injector.
(1) Remove the intake manifold.
(2) Disconnect the right bank injector connector, which

deviates from the standard value at Step 8.

(3) Measure the resistance between injector side connector

terminal No. 1 and No. 2.

Standard value: 10.5

− 13.5 ohms [at 20°C (68°F)]

Q: Is the measured resistance between 10.5 and 13.5 ohms

[at 20

°C (68°F)]?

YES : Go to Step 10.
NO : Replace the injector. Then confirm that the

malfunction symptom is eliminated.

AK303053

3

4

5

8

9

1

2

6

7

10

CONNECTOR: B-32

HARNESS CONNECTOR:
COMPONENT SIDE

AB

B-32 (B)

1

2 3

6

7 8

4 5

9 10

AK203093

B-32
INTERMEDIATE
CONNECTOR

AB

AK303055

M

1

2

CONNECTOR: B-01, B-03, B-04

AB

B-01 (GR)

B-03 (GR)

B-04 (GR)

HARNESS CONNECTOR:
COMPONENT SIDE

AK000559

2

1

INJECTOR SIDE
CONNECTOR

AB