Mitsubishi Galant 9G. Manual — part 1054

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-516

DTC P0204: Injector Circuit Malfunction - Cylinder 4

CAUTION

If DTC P0204 has been set, TCL related DTC
U1120 is also set. After P0204 has been diag-
nosed, don't forget to erase DTC U1120.

AK400910

Injector Circuit - Cylinder 4

GRA

Y

-BLA

CK

RED

139

POWERTRAIN CONTROL
MODULE (PCM)

1

2

INJECTOR
NO. 4

1

B-23

121 122 123 124 125 126 127

128 129 130 131 132 133

134 135 136 137 138 139 140

141 142 143 144 145 146

147 148 149 150 151 152 153

2

3

4

MFI
RELAY

TO PCM

RED-

WHITE

RED-

WHITE

BATTERY

B-17X

1

2

3

4

B-27

(MU802062)

2

1

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-517

.

CIRCUIT OPERATION

• The injector power is supplied from the MFI relay

(terminal No. 4).

• The PCM controls the injector by turning the

power transistor in the PCM "ON" and "OFF".

.

TECHNICAL DESCRIPTION

• The amount of fuel injected by the injector is con-

trolled by the amount of continuity time the coil is
grounded by the PCM.

• A surge voltage is generated when the injectors

are driven and the current flowing to the injector
coil is shut off.

• The PCM checks this surge voltage.

.

DESCRIPTIONS OF MONITOR METHODS

Off-surge does not occur after injector is operated.

.

MONITOR EXECUTION

Continuous

.

MONITOR EXECUTION CONDITIONS
(Other monitor and Sensor)

Other Monitor (There is no temporary DTC stored

in memory for the item monitored below)

• Not applicable

Sensor (The sensor below is determined to be

normal)

• Not applicable

.

AK303109

CONNECTOR: B-27

B-27 (GR)

AB

1

2

3

4

1

2

3

4

1

2

3

4

1

2

3

4

AK303014

CONNECTOR: B-17X

MFI RELAY

MFI RELAY

FRONT OF VEHICLE

B-17X

AB

AK303059

CONNECTOR: B-23

PCM

AB

AIR CLEANER

B-23

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-518

DTC SET CONDITIONS <Circuit continuity

− open circuit and shorted low>

Logic Flow Chart

.

Check Conditions

• Engine is running.

Judgment Criteria

• The supply voltage is 3 volts or less without the

injector driving.

.

START

END

NO

NO

NO

YES

YES

YES

MALFUNCTION

GOOD

MONITORING

CONDITIONS

CONTINUOUS

FAILURE FOR 2secs

INJ. SURGE V

<= 3 V

AK401614

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-519

DTC SET CONDITIONS <Circuit continuity

− shorted high>

Logic Flow Chart

.

Check Conditions

• Engine is running.

Judgment Criteria

• The coil current is 4 ampere or more with the

injector driving.

.

OBD-II DRIVE CYCLE PATTERN

Refer to Diagnostic Function

− OBD-II Drive Cycle −

Procedure 6

− Other Monitor

P.13B-6

.

.

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

• No.4 cylinder injector failed.

• Open or shorted No.4 cylinder injector circuit,

harness damage, or connector damage.

• PCM failed.

START

END

NO

NO

NO

YES

YES

YES

MALFUNCTION

GOOD

MONITORING

CONDITIONS

CONTINUOUS

FAILURE FOR 2secs

CURRENT

>= 4 A

AK401592