Mitsubishi Galant (2004+). Manual - part 878
MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS
TSB Revision
MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>
13A-329
DTC SET CONDITIONS
Logic Flow Chart
.
Check Conditions
• Engine coolant temperature is higher than 60°C
(140
°F).
• Engine speed is between 1,200 and 3,000 r/min.
• Volumetric efficiency is between 25 and 60 per-
cent.
• Under the closed loop air/fuel control.
• The accelerator pedal is open.
• Short-term fuel trim is at between −25 and +25
percent.
• More than 2 seconds have elapsed after the
above mentioned conditions have been met.
• The PCM monitors for this condition for 7 cycles
of 10 seconds each during the drive cycle.
Judgment Criteria
• The cylinder 2, 3 heated oxygen sensor (front)
sends "lean" and "rich" signals alternately 9 times
or less for 10 seconds. <Federal>
or
• The cylinder 2, 3 heated oxygen sensor (front)
sends "lean" and "rich" signals alternately 11
times or less for 10 seconds. <California>
NOTE: If the sensor switching frequency is lower
than the Judgment Criteria due to the MUT-III OBD-II
test Mode
−
H02S Test Results, it is assumed that
the heated oxygen sensor has deteriorated. 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-
onds.
.
OBD-II DRIVE CYCLE PATTERN
Refer to Diagnostic Function
− OBD-II Drive Cycle −
Procedure 4
− Heated Oxygen Sensor Monitor
.
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
AK302021