Mitsubishi Galant. Manual — part 223

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-117

CIRCUIT OPERATION

•

A voltage corresponding to the oxygen
concentration in the exhaust gas is sent to the
PCM (terminal 72) from the output terminal
(terminal 4) of the right bank heated oxygen
sensor (front).

•

Terminal 2 of the right bank heated oxygen
sensor (front) is grounded with PCM (terminal
57).

TECHNICAL DESCRIPTION

•

The right bank heated oxygen sensor (front)
detects the concentration of oxygen in the
exhaust gas; it converts those data to voltage,
and inputs the resulting signals to the PCM.

•

When the right bank heated oxygen sensor
(front) begins to deteriorate, the heated oxygen
sensor signal response becomes poor.

•

The PCM forcibly varies the air/fuel mixture to
make it leaner and richer, and checks the
response speed of the right bank heated oxygen
sensor (front). In addition, the PCM also checks
for an open circuit in the right bank heated
oxygen sensor (front) output line.

DTC SET CONDITIONS

Check Conditions

•

Engine coolant temperature is higher than 50

°

C

(176

°

F).

•

Engine speed is at between 1,250 and 3,000 r/
min.

•

Volumetric efficiency is at between 20 and 60
percent.

•

Intake air temperature is higher than -10

°

C (14

°

F).

•

Barometric pressure is higher than 76 kPa (11
psi).

•

Under the closed loop air/fuel control.

•

PCM dose not judge to be idling state.

Judgment Criteria

•

The right bank heated oxygen sensor (front)
sends "lean" and "rich" signals alternately 10
times (Response time 1.2 or equivalent) or less
for 12 seconds.

•

Only one monitor during one drive cycle

NOTE: If the sensor switch time is longer than the
Judgment Criteria due to the MUT-II OBD-II test
Mode

−

H02S Test Results, it is assumed that the

heated oxygen sensor has deteriorated. If it is
short, it is assumed that the harness is damaged
or has a short circuit.
If the heated oxygen sensor signal voltage has
not changed even once (lean/rich) after the DTC
was erased, the sensor switch time will display as
0 seconds.

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

•

Right bank heated oxygen sensor (front)
deteriorated.

•

Open circuit in right bank heated oxygen sensor
(front) output line.

•

Open circuit in right black heated oxygen sensor
(front) ground line.

•

PCM failed.

DIAGNOSIS

Required Special Tools
MB991502: Scan Tool (MUT-II)

ACX02481AG

CONNECTOR:B-33

RIGHT BANNK
HEATED OXYGEN
SENSOR(FRONT)

AK000280

CONNECTORS : C-40, C-41

C-41

C-40

PCM

AX

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-118

STEP 1. Using scan tool MB991502, check data list item 39:
Heated Oxygen Sensor Bank 1, Sensor 1 (right front).

CAUTION

To prevent damage to scan tool MB991502, always turn the
ignition switch to the "LOCK"(OFF) position before
connecting or disconnecting scan tool MB991502.
(1) Connect scan tool MB991502 to the data link connector.
(2) Start the engine and run at idle.
(3) Set scan tool MB991502 to the data reading mode for item

39, Heated Oxygen Sensor Bank 1, Sensor 1 (right front).

(4) Warm up the engine, 2500r/min.

•

Output voltage repeats 0.4 volt or less and 0.6

−

1.0 volt

10 times or more within 10 seconds.

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

Q: Is the sensor operating properly?

YES : It can be assumed that this malfunction is intermittent.

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

P.00-8

).

NO : Replace the right bank heated oxygen sensor (front).

Then go to Step 2.

STEP 2. Test the OBD-II drive cycle.
(1) Carry out a test drive with the drive cycle pattern. Refer to

P.13B-4

, Procedure 6

−

Other Monitor.

(2) Check the diagnostic trouble code (DTC).

Q: Is the DTC P0133 is output?

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

DTC P0134: O

2

Sensor Circuit No Activity Detected (bank 1 sensor 1)

O

2

SENSOR CIRCUIT NO ACTIVITY DETECTED

(BANK 1 SENSOR 1) CIRCUIT

•

Refer to, DTC P0130

−

Right Bank Heated

Oxygen Sensor (Front) Circuit (

P.13B-107

).

•

Refer to, DTC P0201,P0203,P0205

−

Injector

Circuit (

P.13B-212

).

CIRCUIT OPERATION

•

Refer to, DTC P0130

−

Right Bank Heated

Oxygen Sensor (Front) Circuit (

P.13B-107

).

•

Refer to, DTC P0201,P0203,P0205

−

Injector

Circuit (

P.13B-212

).

TECHNICAL DESCRIPTION

•

The right bank heated oxygen sensor (front)
detects the concentration of oxygen in the
exhaust gas; it converts those data to voltage,
and inputs the resulting signals to the PCM.

•

When the right bank heated oxygen sensor
(front) begins to deteriorate, the heated oxygen
sensor signal response becomes poor.

•

The PCM forcibly varies the air/fuel mixture to
make it leaner and richer, and checks the
response speed of the right bank heated oxygen
sensor (front). In addition, the PCM also checks
for an open circuit in the right bank heated
oxygen sensor (front) output line.

DTC SET CONDITIONS

Check Area

•

Thirty seconds or more have passed since the
starting sequence was completed.

•

Engine coolant temperature is higher than 81

°

C

(178

°

F).

•

Engine speed is higher than 1200 r/min.

•

Volumetric efficiency is higher than 30 percent.

•

Under the closed loop air/fuel control.

AC003081 AB

16 PIN

MB991502

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-119

•

Monitoring time: 30seconds.

Judgment Criteria

•

Multiport fuel injection system does not enter the
closed loop control within about 30 seconds of
meeting all criteria above.

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

•

Right bank heated oxygen sensor (front)
deteriorated.

•

Open circuit in right bank heated oxygen sensor
(front) output line.

•

Open circuit in right black heated oxygen sensor
(front) ground line.

•

PCM failed.

DIAGNOSIS

Required Special Tools
MD998464: Test Harness

STEP 1. Check the exhaust leaks.

Q: Are there any abnormalities?

YES : Go to Step 2.
NO : Repair it. Then go to Step 13.

STEP 2. Check the intake system vacuum leak.

Q: Are there any abnormalities?

YES : Go to Step 3.
NO : Repair it. Then go to Step 13.

STEP 3. Check connector B-33 at the right bank heated
oxygen sensor (front) for damage.
Q: Is the connector in good condition?

YES : Go to Step 4.
NO : Repair or replace it. Refer to GROUP 00E, Harness

Connector Inspection(

P.00E-2

). Then go to Step 13.

AK000617

CONNECTOR:B-33

AB

MULTIPORT FUEL INJECTION(MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L>

13B-120

STEP 4. Check the right bank heated oxygen sensor
(front).
(1) Disconnect the right bank heated oxygen sensor (front)

connector B-33 and connect test harness special tool,
MD998464 to the connector on the right bank heated
oxygen sensor (front) side.

(2) Warm up the engine until engine coolant 80

°

C (176

°

F) or

higher.

CAUTION

Be very careful when connecting the jumper wires;
incorrect connection can damage the right bank heated
oxygen sensor (front).
(3) Use the jumper wires to connect terminal 1 (red clip) to the

positive battery terminal and terminal 3 (blue clip) to the
negative battery terminal.

(4) Connect a digital volt meter between terminal 2 (black clip)

and terminal 4 (white clip).

(5) While repeatedly revving the engine, measure the right

bank heated oxygen sensor (front) output voltage.

Standard value: 0.6

−−−−

1.0 V

Q: Is the voltage at the standard value?

YES : Go to Step 5.
NO : Replace the right bank heated oxygen sensor (front).

Then go to Step 13.

STEP 5. Check connector B-26 at injector intermediate
connector for damage.
Q: Is the connector in good condition?

YES : Go to Step 6.
NO : Repair or replace it. Refer to GROUP 00E, Harness

Connector Inspection(

P.00E-2

). Then go to Step 13.

ACX02481AG

CONNECTOR:B-33

RIGHT BANNK
HEATED OXYGEN
SENSOR(FRONT)

AKX01624

HEATED
OXYGEN
SENSOR
EQUIPMENT
SIDE
CONNECTOR

MD998464

BLUE

RED

AC

AKX01625AC

BLUE

RED

BLACK

JUMPER
WIRES

WHITE

MD998464

AK000618

AB

CONNECTOR:B-26