Mitsubishi Outlander GS45X. Manual — part 825

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L ENGINE>

13B-233

CIRCUIT OPERATION

• A voltage corresponding to the oxygen concen-

tration in the exhaust gas is sent to the ECM (ter-
minal No. 54) from the output terminal (terminal
No. 4) of the right bank heated oxygen sensor
(front).

• Terminal No. 2 of the right bank heated oxygen

sensor (front) is grounded with ECM (terminal
No. 55).

• The ECM applies an off set voltage of 0.5 volt to

terminal No. 2 of the right bank oxygen sensor
(front).

.

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 ECM.

• When the right bank heated oxygen sensor

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

• The ECM also checks for the right bank heated

oxygen sensor (front) rich learn switching fre-
quency.

.

DESCRIPTIONS OF MONITOR METHODS

Right bank heated oxygen sensor (front) rich/lean
switching frequency is under specified value.

.

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)

• Heated oxygen sensor (front) heater monitor

• Misfire monitor

• Fuel system monitor

Sensor (The sensor below is determined to be

normal)

• Engine coolant temperature sensor

• Mass airflow sensor

• Intake air temperature sensor

• Barometric pressure sensor

• Throttle position sensor

• Accelerator pedal position sensor

.

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L ENGINE>

13B-234

DTC SET CONDITIONS

Logic Flow Chart

.

Check Conditions

• Engine coolant temperature is higher than 60°C

(140

°F).

• Engine speed is between 1,188 and 3,000 r/min.

• Volumetric efficiency is between 21 and 69 per-

cent.

• Under the closed loop air/fuel control.

• The accelerator pedal is depressed.

• Short-term fuel trim is between −25 and +25 per-

cent.

• More than 2 seconds have elapsed after the

abovementioned conditions have been met.

• During the drive cycle, the ECM performs moni-

toring with the accumulated total time of 12 sec-
onds, 5 times.

Judgement Criteria

• The average of the right bank heated oxygen

sensor (front) rich/lean switching frequency is
less than 11 times <Except for California> or 12
times <California> for the accumulated time of 12
seconds.

• The right bank heated oxygen sensor (front)

rich/lean switching frequency is less than 20
times for the accumulated time of 12 seconds.

NOTE: If the sensor switching frequency is lower
than the Judgment Criteria due to the M.U.T.-III
OBD-II test Mode

−

HO2S Test Results, it is

assumed that the heated oxygen sensor has deterio-
rated. If it is higher, 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 sec-
ond.

.

F0: Threshold value for average switching frequency

Start

Monitoring

conditions

Malfunction

Good

End

No

No

Yes

Yes

Ff < F0

Calculate average switching

frequency (Ff) over specified times

AK604323

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L ENGINE>

13B-235

OBD-II DRIVE CYCLE PATTERN

Refer to Diagnostic Function

− OBD-II Drive Cycle −

Pattern 1

P.13B-11

.

.

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

• Right bank heated oxygen sensor (front) deterio-

rated.

• ECM failed.

DIAGNOSIS

Required Special Tools:

• MB991316: Test Harness

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

connector B-03 and connect test harness special tool,
MB991316, to the connector on the right bank heated
oxygen sensor (front) side.

(2) Warm up the engine until engine coolant temperature

reaches 80

°C (176°F) or higher.

(3) Rev the engine for 5 minutes or more with the engine speed

of 4,500 r/min.

(4) Connect a digital voltage meter between terminal No. 2

(black clip) and terminal No. 4 (white clip).

(5) Warn up the engine, 2,500 r/min.

• Output voltage repeats 0 − 0.4 volt or less and 0.6 − 1.0

volts 13 times or more within 12 seconds.

CAUTION

• Be very careful when connecting the jumper wires;

incorrect connection can damage the heated oxygen
sensor

• Be careful the heater can be damaged if a voltage

beyond 8 volts is applied to the heated oxygen sensor
heater.
NOTE: If the temperature of sensing area does not reach
the high temperature [of approximately 400

°

C (752

°

F) or

more] even though the oxygen sensor is normal, the output
voltage would be possibly low in spite of the rich air-fuel
ratio. Therefore, if the output voltage is low, use a jumper
wire to connect the terminal No.1 (red clip) and the terminal
No. 3 (blue clip) of the heated oxygen sensor with the posi-
tive terminal and the negative terminal of 8 volts power sup-
ply respectively, then check again.

Q: Is the sensor operating properly?

YES : Go to Step 2.
NO : Replace the right bank heated oxygen sensor (front).

Then go to Step 2.

AK700551

Heated
oxygen
sensor
component
side
connector

MB991316

Black

White

AB

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.0L ENGINE>

13B-236

STEP 2. 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 − Pattern 1

P.13B-11

.

(2) Check the diagnostic trouble code (DTC).
Q: Is DTC P0133 set?

YES : Replace the ECM. When the ECM is replaced,

register the ID code. Refer to GROUP 42B, Diagnosis
− ID Codes Registration Judgment Table <Vehicles

with KOS>

P.42B-15

or GROUP 42C, Diagnosis

− ID

Codes Registration Judgment Table <Vehicles with
WCM>

P.42C-10

.

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.00-15

.

DTC P0134: Heated Oxygen Sensor Circuit No Activity Detected (bank 1, sensor 1)

.

Heated Oxygen Sensor Circuit No Activity
Detected (bank 1, sensor 1) Circuit

• Refer to DTC P0131 − Heated Oxygen Sensor

Circuit Low Voltage (bank 1, sensor 1)

P.13B-222

.

• Refer to DTC P0201 − Injector Circuit Malfunction

− Cylinder 1

P.13B-345

, DTC P0203

− Injector

Circuit Malfunction

− Cylinder 3

P.13B-360

, DTC

P0205

− Injector Circuit Malfunction − Cylinder 5

P.13B-375

.

.

CIRCUIT OPERATION

• Refer to DTC P0131 − Heated Oxygen Sensor

Circuit Low Voltage (bank 1, sensor 1)

P.13B-222

.

• Refer to DTC P0201 − Injector Circuit Malfunction

− Cylinder 1

P.13B-345

, DTC P0203

− Injector

Circuit Malfunction

− Cylinder 3

P.13B-360

, DTC

P0205

− Injector Circuit Malfunction − Cylinder 5

P.13B-375

.

.

TECHNICAL DESCRIPTION

• The ECM effects air/fuel ratio feedback control in

accordance with the signals from the right bank
heater oxygen sensor (front).

• If the right bank heated oxygen sensor (front) has

deteriorated, corrections will be made by the right
bank heated oxygen sensor (rear).

• DTC P0134 becomes stored in memory if a fail-

ure is detected in the above air/fuel ratio feed-
back control system.

.

DESCRIPTIONS OF MONITOR METHODS

Right bank heated oxygen sensor (front) output volt-
age does not exceed lean/rich criteria (about 0.5 volt)
within specified period.

.

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)

• Misfire monitor

Sensor (The sensor below is determined to be

normal)

• Mass airflow sensor

• Engine coolant temperature sensor

• Intake air temperature sensor

• Barometric pressure sensor

• Throttle position sensor

.