Mitsubishi Galant. Manual — part 314

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-481

INSPECTION PROCEDURE 32 : Ignition Circuit System

AK000528

6

5

7

1

4

4 5 6

1 2

1

3

2

4 5

7

2

6

3

5

1
4

6

BLA

CK-

WHITE

3

BLA

CK-

WHITE

BLA

CK-

WHITE

8

3

2

BLA

CK-

WHITE

BLA

CK

BLA

CK-

BLUE

WHITE

1

43

4

2

SPARK PLUG

11

IGNITION
POWER
TRANSISTOR

DISTRIBUTOR

B-27
(MU802054)

ACC

IG1

C-58

2

5

JUNCTION
BLOCK

C-04
MU801333

29

R

C-73
MU801331

IGNITION
SWITCH

6

3

IG2

ST

3

LOCK

POWERTRAIN CONTROL
MODULE(PCM)

IGNITION COIL

15 16

26 27 28 29

32 33 34

17 18 19 20 21 22 23 24 25

30 31

36 37

35

38

10

11 12 13

1 2 3

4 5 6 7 8 9

14

C-66

C-39
(MU803784)

2

3 4

5 6

7 8

9

11 12 13 14 15 16 17 18 19 20

30

21 22 23

24 25

26 27 28 29

3132 33

34 35

1

10

C-40
(MU803781)

42 43
48 49 50 51 52 53 54 55 56 57

46

45

44

58 59

60 61 62 63

64 65 66

47

41

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-482

CIRCUIT OPERATION

•

The battery positive voltage is applied on the
ignition coil by the ignition switch-IG.

•

When the PCM turns the power transistor in the
PCM"OFF", battery positive voltage is applied on
the ignition power transistor (terminals 3), and the
ignition power transistor turns "ON".

•

When the ignition power transistor turns on, the
ignition coil's primary circuit is grounded by the
ignition power transistor terminal 4. Then the
primary current flows to the ignition coil.

TROUBLESHOOTING HINTS (The most likely
causes for this case:)

•

Malfunction of the ignition coil.

•

Malfunction of the ignition power transistor.

•

Improper connector contact, open circuit or short-
circuited harness wire.

•

Malfunction of the PCM.

AK000619 AD

CONNECTOR:B-27

AK000631AB

CONNECTOR:C-78

AK000280

CONNECTORS : C-39, C-40

C-39 C-40

PCM

AU

AK000632 AB

CONNECTOR:C-66

AK000634 AB

CONNECTOR:C-58

AK000633 AE

CONNECTOR:C-04

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-483

DIAGNOSIS

STEP 1. Check connector B-27 at distributor for damage.
Q: Is the connector in good condition?

YES : Go to Step 2.
NO : Repair or replace it. Refer to GROUP 00E, Harness

Connector Inspection(

P.00E-2

). Then confirm that the

malfunction symptom is eliminated.

STEP 2. Check the ignition coil.
Refer to GROUP 16, Ignition System

−

On-vehicle service

−

Ignition coil check(

P.16-34

).

Q: Are there any abnormalities?

YES : Go to Step 3.
NO : Repair the ignition coil. Then confirm that the

malfunction symptom is eliminated.

STEP 3. Check the ignition power transistor.
Refer to GROUP 16, Ignition System

−

On-vehicle service

−

Power transistor check(

P.16-34

).

Q: Are there any abnormalities?

YES : Go to Step 4.
NO : Repair the ignition power transistor. Then confirm that

the malfunction symptom is eliminated.

STEP 4. Check the power supply voltage at distributor
connector B-27.
(1) Disconnect the connector B-27 and measure at the harness

side.

(2) Turn the ignition switch to the "ON" position.
(3) Measure the voltage between terminal 1 and ground.

•

Voltage should be battery positive voltage.

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

Q: Is the voltage normal?

YES : Go to Step 5.
NO : Check connector C-04, C-66 and C-73 at

intermediate connectors for damage, and repair or
replace as required. Refer to GROUP 00E, Harness
Connector Inspection (

P.00E-2

). If intermediate

connectors are in good condition, repair harness wire
between ignition switch connector C-58 terminal 2
and distributor connector B-27 terminal 1because of
open circuit. Then confirm that the malfunction
symptom is eliminated.

AK000619 AD

CONNECTOR:B-27

AK000387

B-27 HARNESS
SIDE CONNECTOR

1

2

3

4

5

6

7

AC

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-484

STEP 5. Check the continuity at distributor harness side
connector B-27.
(1) Disconnect the connector B-27 and measure at the harness

side.

(2) Check for the continuity between terminal 4 and ground.

•

Should be less than 2 ohm.

Q: Is the continuity normal?

YES : Go to Step 6.
NO : Repair harness wire between distributor connector B-

27 terminal 4 and ground because of open circuit or
harness damage. Then confirm that the malfunction
symptom is eliminated.

STEP 6. Check connector C-39, 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 confirm that the

malfunction symptom is eliminated.

STEP 7. Check for open circuit between distributor
connector B-27 terminal 3 and PCM connector C-39
terminal 11.
Q: Is the harness wire in good condition?

YES : Go to Step 8.
NO : Repair it. Then confirm that the malfunction symptom

is eliminated.

AK000388

B-27 HARNESS
SIDE CONNECTOR

1

2

3

4

5

6

7

AC

AK000280

CONNECTORS : C-39, C-40

C-39 C-40

PCM

AU

AK000619 AD

CONNECTOR:B-27

AK000280

CONNECTOR : C-39

PCM

AW