Mitsubishi Galant 9G. Manual — part 926

GENERAL DESCRIPTION

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MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-4

OTHER CONTROL FUNCTIONS

Fuel Pump Control

• Turns the fuel pump relay ON so that current is

supplied to the fuel pump while the engine is
cranking or running.

A/C Compressor Clutch Relay Control

• Turns the compressor clutch of the A/C ON and

OFF.

Fan Relay Control

• The radiator fan and condenser fan speeds are

controlled in response to the engine coolant tem-
perature and vehicle speed.

Generator Output Current Control

• Prevent generator output current from increasing

suddenly and idle speed from dropping at times
such as when the headlights are turned on.

Evaporative Emission Purge Control

• (Refer to GROUP 17, Emission Control System −

Evaporative Emission System

− General Descrip-

tion

P.17-83

.)

EGR Control

• (Refer to GROUP 17, Emission Control System −

Exhaust Gas Recirculation (EGR) System - Gen-
eral Description

P.17-89

.)

GENERAL DESCRIPTION

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MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

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MULTIPORT FUEL INJECTION (MFI) SYSTEM DIAGRAM

NOTE: For the vacuum routing, refer to GROUP 17, Emission Control System

−

Vacuum Hoses

−

Vacuum

Hose Routing

P.17-77

.

AK301872

MANIFOLD
ABSOLUTE
PRESSURE
SENSOR

THROTTLE
ACTUATOR
CONTROL
MOTOR

CAMSHAFT
POSITION
SENSOR

LEFT BANK HEATED OXYGEN
SENSOR (FRONT)

FUEL TANK
DIFFERENTIAL
PRESSURE
SENSOR

FUEL TANK
TEMPERATURE
SENSOR

EVAPORATIVE EMISSION
VENTILATION VALVE

FUEL TANK

EVAPORATIVE
EMISSION
CANISTER

3 THROTTLE POSITION SENSOR
(MAIN/SUB)

MASS AIRFLOW
SENSOR

ENGINE
COOLANT
TEMPERATURE
SENSOR

IGHT BANK
EATED
XYGEN

ENSOR

FRONT)

RIGHT BANK HEATED
OXYGEN SENSOR (REAR)

FUEL PRESSURE
REGULATOR

EVAPORATIVE
EMISSION
VENTILATION
SOLENOID

LEFT BANK HEATED OXYGEN
SENSOR (REAR)

FUEL PUMP

CRANKSHAFT POSITION
SENSOR

FUEL
LEVEL
SENSOR

AIR
INLET

INTAKE AIR TEMPERATURE
SENSOR

EVAPORATIVE
EMISSION
PURGE SOLENOID

INJECTOR

EGR VALVE
(STEPPER MOTOR)

1 MASS AIRFLOW SENSOR
2 INTAKE AIR TEMPERATURE SENSOR
3 THROTTLE POSITION SENSOR (MAIN/SUB)
4 MANIFOLD ABSOLUTE PRESSURE SENSOR
5 ENGINE COOLANT TEMPERATURE SENSOR
6 CAMSHAFT POSITION SENSOR
7 CRANKSHAFT POSITION SENSOR
8 RIGHT BANK HEATED OXYGEN SENSOR (FRONT)
9 RIGHT BANK HEATED OXYGEN SENSOR (REAR)
10 LEFT BANK HEATED OXYGEN SENSOR (FRONT)
11 LEFT BANK HEATED OXYGEN SENSOR (REAR)
12 FUEL TANK DIFFERENTIAL PRESSURE SENSOR
13 FUEL TANK TEMPERATURE SENSOR
14 FUEL LEVEL SENSOR

ACCELERATOR PEDAL POSITION SENSOR
(MAIN/SUB)
KNOCK SENSOR
POWER STEERING PRESSURE SWITCH
OUTPUT SHAFT SPEED SENSOR
TRANSMISSION RANGE SWITCH
GENERATOR FR TERMINAL
IGNITION SWITCH-IG
IGNITION SWITCH-ST
POWER SUPPLY

1 THROTTLE ACTUATOR
CONTROL MOTOR
2 EGR VALVE (STEPPER
MOTOR)
3 INJECTOR
4 EVAPORATIVE EMISSION
PURGE SOLENOID
5 EVAPORATIVE EMISSION
VENTILATION SOLENOID

IGNITION COIL, IGNITION
POWER TRANSISTER
MULTIPORT FUEL
INJECTION (MFI) RELAY
FUEL PUMP RELAY
THROTTLE ACTUATOR
CONTROL MOTOR RELAY
GENERATOR G TERMINAL
HEATED OXYGEN SENSOR
HEATER
FAN CONTROL RELAY
(RADIATOR, A/C CONDENSER)
A/C COMPRESSOR CLUTCH
RELAY
DIAGNOSTIC OUTPUT

PCM (WITH
BAROMETRIC
PRESSURE
SENSOR)

SENSE

DECIDE

ACT

AC

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-6

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TROUBLESHOOTING STRATEGY

M1131150001204

NOTE: If a DTC is erased, its "freeze frame" data will
be also erased and system readiness test status will
be reset. Store the "freeze frame" data before eras-
ing the DTC.
Use these steps to plan your diagnostic strategy. If
you follow them carefully, you will be sure to have
exhausted most of the possible ways to find an MFI
fault.
1. Gather as much information as possible about the

complaint from the customer.

2. Verify that the condition described by the

customer exists.

3. Check the vehicle for any MFI Diagnostic Trouble

Code (DTC).

4. If you cannot verify the condition and there are no

DTCs, the malfunction is intermittent. For
information on how to cope with intermittent
malfunctions, refer to GROUP 00, How to Use
Troubleshooting/Inspection Service Points

− How

to Cope with Intermittent Malfunctions

P.00-14

.

5. If you can verify the condition but there are no

DTCs, or the system cannot communicate with
the scan tool, refer to the trouble symptom
classification table.

6. If there is a DTC, record the number of the code,

then erase the code from the memory using the
scan tool.

7. Reconfirm the malfunction symptom and carry out

a test drive with the drive cycle pattern.

8. If DTC is set again, carry out an inspection with

appropriate diagnostic trouble code procedures.

9. If DTC is not set again, the malfunction is

intermittent. For information on how to cope with
intermittent malfunctions, refer to GROUP 00,
How to Use Troubleshooting/Inspection Service
Points

− How to Cope with Intermittent

Malfunctions

P.00-14

.

10.After repairs are completed, conduct a road test

duplicating the complaint set conditions to confirm
the malfunction has been corrected.

NOTE: If the powertrain control module (PCM) is
replaced, Immobilizer Encrypted Code Registration
should be carried out, Refer to GROUP 54A, Ignition
Switch

−

On-vehicle Service

−

Immobilizer Encrypted

Code Registration

P.54A-37

.

DIAGNOSTIC FUNCTION

M1131155500881

.

MALFUNCTION INDICATOR LAMP (SERVICE
ENGINE SOON OR CHECK ENGINE LAMP)

Among the on-board diagnostic items, Malfunction Indicator
Lamp (SERVICE ENGINE SOON or Check Engine Lamp) illu-
minates to notify the driver of an emission control malfunction.
However, when an irregular signal returns to normal and the
powertrain control module judges that it has returned to normal,
the Malfunction Indicator Lamp (SERVICE ENGINE SOON or
Check Engine Lamp) is switched off.
Immediately after the ignition switch is turned on, the Malfunc-
tion Indicator Lamp (SERVICE ENGINE SOON or Check
Engine Lamp) is lit for 20 seconds to indicate that the Malfunc-
tion Indicator Lamp (SERVICE ENGINE SOON or Check
Engine Lamp) operates normally.

.

AK303972AB

MALFUNCTION INDICATOR
LAMP (SERVICE ENGINE SOON
or Check Engine Lamp)

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

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Items Indicated by the Malfunction Indicator Lamp (SERVICE ENGINE SOON or Check
Engine Lamp)

DTC

ITEM

-

Powertrain control module (PCM) malfunction

P0069

Abnormal correlation between manifold absolute pressure sensor and barometric
pressure sensor

P0101*

Mass airflow circuit range/performance problem

P0102*

Mass airflow circuit low input

P0103*

Mass airflow circuit high input

P0106

Manifold absolute pressure circuit range/performance problem

P0107

Manifold absolute pressure circuit low input

P0108

Manifold absolute pressure circuit high input

P0111*

Intake air temperature circuit range/performance problem

P0112*

Intake air temperature circuit low input

P0113*

Intake air temperature circuit high input

P0116*

Engine coolant temperature circuit range/performance problem

P0117*

Engine coolant temperature circuit low input

P0118*

Engine coolant temperature circuit high input

P0122*

Throttle position sensor (main) circuit low input

P0123*

Throttle position sensor (main) circuit high input

P0125*

Insufficient coolant temperature for closed loop fuel control

P0128

Coolant thermostat (Coolant temperature below thermostat regulating temperature)

P0130

Heated oxygen sensor circuit (bank 1 sensor 1)

P0131

Heated oxygen sensor circuit low voltage (bank 1 sensor 1)

P0132

Heated oxygen sensor circuit high voltage (bank 1 sensor 1)

P0133

Heated oxygen sensor circuit slow response (bank 1 sensor 1)

P0134*

Heated oxygen sensor circuit no activity detected (bank 1 sensor 1)

P0135

Heated oxygen sensor heater circuit (bank 1 sensor 1)

P0136

Heated oxygen sensor circuit (bank 1 sensor 2)

P0137

Heated oxygen sensor circuit low voltage (bank 1 sensor 2)

P0138

Heated oxygen sensor circuit high voltage (bank 1 sensor 2)

P0139

Heated oxygen sensor circuit slow response (bank 1 sensor 2)

P0141

Heated oxygen sensor heater circuit (bank 1 sensor 2)

P0150

Heated oxygen sensor circuit (bank 2 sensor 1)

P0151

Heated oxygen sensor circuit low voltage (bank 2 sensor 1)

P0152

Heated oxygen sensor circuit high voltage (bank 2 sensor 1)

P0153

Heated oxygen sensor circuit slow response (bank 2 sensor 1)

P0154*

Heated oxygen sensor circuit no activity detected (bank 2 sensor 1)

P0155

Heated oxygen sensor heater circuit (bank 2 sensor 1)

P0156

Heated oxygen sensor circuit (bank 2 sensor 2)

P0157

Heated oxygen sensor circuit low voltage (bank 2 sensor 2)