Mitsubishi Galant (2004+). Manual - part 1133

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-225

STEP 3. Check harness connector B-09 at right bank
heated oxygen sensor (front) and harness connector B-21,
B-22 at PCM for damage.

Q: Is the harness connector in good condition?

YES : Replace the PCM. Then go to Step 4.
NO : Repair or replace it. Refer to GROUP 00E, Harness

Connector Inspection

P.00E-2

. Then go to Step 4.

AK303048

B-09 (B)

CONNECTOR: B-09

THROTTLE BODY

RIGHT BANK
HEATED OXYGEN
SENSOR (FRONT)

HARNESS
CONNECTOR:
COMPONENT SIDE

AK303052

54 53 52 51

62 61 60 59 58

69 68 67 66 65 64

75 74 73 72 71

82 81 80 79 78 77

104

93 92 91

99 98 97

103 102 101 100

108 107 106 105

113 112 111 110 109

CONNECTORS: B-21, B-22

B-21 HARNESS CONNECTOR:
COMPONENT SIDE

B-22 HARNESS CONNECTOR:
COMPONENT SIDE

PCM

AIR CLEANER

B-22 (B)

B-21 (B)

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-226

STEP 4. 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 − Procedure 4 −

Heated Oxygen Sensor Monitor

P.13B-5

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

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

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

CAUTION

If DTC P0134 has been set, TCL related DTC
U1120 is also set. After P0134 has been diag-
nosed, don't forget to erase DTC U1120.

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

• Refer to, DTC P0130 − Right Bank Heated Oxy-

gen Sensor (Front) Circuit

P.13B-189

• Refer to, DTC P0201

P.13B-471

P0203

P.13B-492

, P0205

P.13B-513

− Injector

Circuit.

CIRCUIT OPERATION

• Refer to, DTC P0132 − Right Bank Heated Oxy-

gen Sensor (Front) Circuit

P.13B-214

• Refer to, DTC P0201

P.13B-471

P0203

P.13B-492

, P0205

P.13B-513

− Injector

Circuit.

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 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 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)

• Mass airflow sensor

• Engine coolant temperature sensor

• Intake air temperature sensor

• Barometric pressure sensor

• Throttle position sensor

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-227

DTC SET CONDITIONS

Logic Flow Chart

Check Conditions

• 20 seconds or more have passed since the

engine starting 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.

• 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.13B-5

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).

HEATED OXYGEN SENSOR (FRONT)

OUTPUT VOLTAGE CROSSES 0.5V?

START

END

YES

Yes

YES

MALFUNCTION

GOOD

30secs HAVE PASSED?

MONITORING

CONDITIONS

AK203999

MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS

TSB Revision

MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>

13B-228

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.

• Open circuit in right bank injector.

• Harness damage in right bank injector circuit.

• Connector damage.

• PCM failed.

• Exhaust leak.

• Air drawn in from gaps in gasket, seals, etc.

• Incorrect fuel pressure.

DIAGNOSIS

Required Special Tools:

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

• MB991824: V.C.I.

• MB991827: USB Cable

• MB991910: Main Harness A

• 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).

• Warming 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) DTC

P.13B-250

, P0137

− Heated

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