Mitsubishi Montero Sport (2004+). Manual — part 199

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI)

13A-209

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 P0130 − Heated Oxygen Sensor

Circuit (bank 1, sensor 1)

P.13A-198

.

• Refer to, DTC P0201, P0202, P0203, P0204,

P0205, P0206

− Injector Circuit

P.13A-428

.

.

CIRCUIT OPERATION

• Refer to, DTC P0130-Heated Oxygen Sensor Cir-

cuit (bank 1, sensor 1)

P.13A-198

.

• Refer to, DTC P0201, P0202, P0203, P0204,

P0205, P0206-Injector Circuit

P.13A-428

.

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TECHNICAL DESCRIPTION

• The PCM 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 is stored when abnormality of the

air/fuel ratio feedback control is detected.

.

DESCRIPTIONS OF MONITOR METHODS
Right bank heated oxygen sensor (front) output volt-

age does not cross 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)

• Volume airflow sensor

• Engine coolant temperature sensor

• Intake air temperature sensor

• Barometric pressure sensor

• Throttle position sensor

.

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI)

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DTC SET CONDITIONS

Logic Flow Chart

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Check Conditions

• 20 seconds or more have passed since the start-

ing sequence was completed.

• Engine coolant temperature is higher than 76°C

(169

°F).

• Engine speed is higher than 1,200 r/min.

• Volumetric efficiency is higher than 30 percent

and lower than 95 percent.

• Throttle position sensor output voltage is lower

than 4 volts.

• Except while fuel is being shut off.

• Monitoring time: 30 seconds.

Judgment Criteria

• Right bank heated oxygen sensor (front) output

voltage does not get across 0.5 volt within about
30 seconds.

.

OBD-II DRIVE CYCLE PATTERN
Refer to Diagnostic Function

− OBD-II Drive Cycle −

Procedure 6

− Other Monitor

P.13A-4

.

.

HEATED OXYGEN SENSOR (FRONT)

OUTPUT VOLTAGE CROSSES 0.5V?

START

END

NO

NO

NO

YES

Yes

YES

MALFUNCTION

GOOD

30secs HAVE PASSED?

MONITORING

CONDITIONS

AK203999

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI)

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

• Right bank heated oxygen sensor (front) deterio-

rated.

• Harness damage in right bank heated oxygen

sensor (front) output line.

• Right bank heated oxygen sensor (rear) deterio-

rated.
NOTE: When the right bank heated oxygen sen-
sor (front) begins to deteriorate, the heated oxy-
gen sensor output voltage will deviate from the
voltage when the sensor was new (normally 0.5
volt at stoichiometric ratio). This deviation will be
corrected by the right bank heated oxygen sensor
(rear).

If the right bank heated oxygen sensor (rear)
responds poorly because it has deteriorated, it
will improperly correct the right bank heated oxy-
gen sensor (front). Thus, even when closed loop
control is being effected, the fluctuation of the
right bank heated oxygen sensor (front) output
voltage decreases, without intersecting with 0.5
volt. As a result, there is a possibility of DTC
P0134 becoming registered.

• Connector damage.

• Harness damage in injector circuit.

• Injector failed.

• PCM failed.

• Exhaust leaks.

• Incurrect fuel pressure.

• Intake system vacuum leak.

DIAGNOSIS

Required Special Tools:

• MB991958: Scan Tool (MUT-III Sub Assembly)

• MB991824: V.C.I

• MB991827: USB Cable

• MB991911: Main Harness B

• MD998464: Test Harness

STEP 1. Using scan tool MB991958, check data list item 69:
Heated Oxygen Sensor Bank 1, Sensor 2 (right rear).

CAUTION

To prevent damage to scan tool MB991958, always turn the
ignition switch to the "LOCK" (OFF) position before con-
necting or disconnecting scan tool MB991958.
(1) Connect scan tool MB991958 to the data link connector.
(2) Start the engine and run at idle.
(3) Set scan tool MB991958 to the data reading mode for item

69, Heated Oxygen Sensor Bank 1, Sensor 2 (right rear).

• Warm up the engine. When the engine is revved, the

output voltage should repeat 0 volt and 0.6 to 1.0 volt
alternately.

(4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the sensor operating properly?

YES : Go to Step 2.
NO : Refer to DTC P0136

− Heated Oxygen Sensor Circuit

(bank 1, sensor 2)

P.13A-230

, DTC P0137

− Heated

Oxygen Sensor Circuit Low Voltage (bank 1, sensor
2)

P.13A-243

, DTC P0138

− Heated Oxygen Sensor

Circuit High Voltage (bank 1, sensor 2)

P.13A-252

,

DTC P0139

− Heated Oxygen Sensor Circuit Slow

Response (bank 1, sensor 2)

P.13A-258

.

AK303629AB

MB991911

MB991827

MB991824

16-PIN

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

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MULTIPORT FUEL INJECTION (MFI)

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STEP 2. Check for exhaust leaks.
Q: Are there any abnormalities?

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

STEP 3. Check for intake system vacuum leaks.
Q: Are there any abnormalities?

YES : Go to Step 4.
NO : Repair it. Then go to Step 13.

STEP 4. Check connector A-07 at the right bank heated
oxygen sensor (front) for damage.
Q: Is the connector in good condition?

YES : Go to Step 5.
NO : Repair or replace it. Refer to GROUP 00E, Harness

Connector Inspection

P.00E-2

. Then go to Step 13.

AK200490

1

2

3

4

A-07(B)

AB

CONNECTOR: A-07

HARNESS
CONNECTOR:
COMPONENT SIDE

RIGHT BANK
HEATED OXYGEN
SENSOR (FRONT)