Mitsubishi Galant 9G. Manual — part 774

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-538

Judgement Criteria (change in the angular accel-

eration of the crankshaft is used for misfire
detection)

• Misfire has occurred more frequently than

allowed during the last 200 revolutions [when the
catalyst temperature is higher than 950

°C

(1,742

°F)].

or

• Misfire has occurred in 15 or more of the last

1,000 revolutions (corresponding to 1.5 times the
limit of emission standard). <Federal>

or

• Misfire has occurred in 10 or more of the last

1,000 revolutions (corresponding to 1.5 times the
limit of emission standard). <California>

.

OBD-II DRIVE CYCLE PATTERN

Refer to Diagnostic Function

− OBD-II Drive Cycle −

Procedure 6

− Other Monitor

P.13A-6

.

.

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

• Ignition system related part(s) failed.

• Low compression pressure.

• PCM failed.

DIAGNOSIS

STEP 1. Check the No. 4 cylinder ignition coil spark.
(1) Remove the No. 4 cylinder ignition coil.
(2) Remove the No. 4 cylinder spark plug and connect to the

No. 4 cylinder ignition coil.

(3) Ground the spark plug side electrode securely.

• When the engine is cranked, the spark plug should

spark.

Q: Did it spark?

YES : Go to Step 3.
NO : Go to Step 2.

STEP 2. Check the No. 4 cylinder spark plug.

CAUTION

Do not attempt to adjust the gap of the iridium plug. Clean-
ing of the iridium plug may result in damage to the iridium
and platinum tips. Therefore, if carbon deposits must be
removed, use a plug cleaner and complete cleaning within
20 seconds to protect the electrode. Do not use a wire
brush.
(1) Check the plug gap and replace if the limit is exceeded.

Standard value: 0.7

− 0.8 mm (0.028 − 0.031 inch)

Limit: 1.0 mm (0.039 inch)

Q: Is the plug gap at the standard value?

YES : Refer to, INSPECTION PROCEDURE 31

− Ignition

Circuit System

P.13A-1073

.

NO : Replace the No. 4 cylinder spark plug. Then go to

Step 5.

AKX00432

SPARK PLUG

AB

AKX01327AB

IRIDIUM
TIP

PLATINUM
TIP

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-539

STEP 3. Check the compression.
Refer to GROUP 11A, On-Vehicle Service

− Compression

Pressure Check

P.11A-16

.

Q: Are there any abnormalities?

YES : Repair or replace it. Then go to Step 5.
NO : Go to Step 4.

STEP 4. Check the trouble symptoms.
(1) Carry out a test drive with the drive cycle pattern. Refer to

Diagnostic Function

− OBD-II Drive Cycle − Procedure 6 −

Other Monitor

P.13A-6

.

(2) Check the diagnostic trouble code (DTC).
Q: Is DTC P0304 set?

YES : Replace the PCM. Then go to Step 5.
NO : It can be assumed that this malfunction is intermittent.

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

− How to

Cope with Intermittent Malfunctions

P.00-14

.

STEP 5. Test the OBD-II drive cycle.
(1) Carry out a test drive with the drive cycle pattern. Refer to

Diagnostic Function

− OBD-II Drive Cycle − Procedure 6 −

Other Monitor

P.13A-6

.

(2) Check the diagnostic trouble code (DTC).
Q: Is DTC P0304 set?

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

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-540

DTC P0325: Knock Sensor Circuit

CAUTION

If DTC P0325 has been set, TCL related DTC
U1120 is also set. After P0325 has been diag-
nosed, don't forget to erase DTC U1120.

2

1

AK303854

52

51

53 54 55 56

57

58 59 60 61 62

63

64 65 66 67 68 69

70

71 72 73 74 75

76

77 78 79 80 81 82

83

WHITE

BLA

CK

BLA

CK

59

KNOCK SENSOR

2

1

B-120

MU802661

B-21

POWERTRAIN CONTROL
MODULE (PCM)

Knock Sensor Circuit

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>

13A-541

.

CIRCUIT OPERATION

• The knock sensor sends a signal voltage to the

PCM (terminal No. 59).

.

TECHNICAL DESCRIPTION

• The knock sensor converts the vibration of the

cylinder block into a voltage and outputs it. If
there is a malfunction of the knock sensor, the
voltage output will not change.

• The PCM checks whether the voltage output

changes.

.

DTC SET CONDITIONS

Check Conditions

• 2 seconds or more have passed since the start-

ing sequence was completed.

• Engine speed is higher than 2,500 r/min.

Judgment Criteria

• Knock sensor output voltage (knock sensor peak

voltage in each 1/2 turn of the crankshaft) has not
changed more than 0.06 volt in the last consecu-
tive 200 periods.

.

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

• Knock sensor failed.

• Open or shorted knock sensor circuit, harness

damage or connector damage.

• PCM failed.

AK303855AB

CONNECTOR: B-120

KNOCK SENSOR

INTAKE
MANIFOLD

INTAKE
MANIFOLD

B-120 (GR)

AK303119

CONNECTOR: B-21

PCM

AB

AIR CLEANER

B-21