Mitsubishi Outlander GS45X. Manual — part 644
MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS
TSB Revision
MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>
13A-399
STEP 19. 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 23
(2) Check the diagnostic trouble code (DTC).
Q: Is DTC P0365 set?
YES : Retry the troubleshooting.
NO : The inspection is complete.
DTC P0401: Exhaust Gas Recirculation Flow Insufficient Detected
.
TECHNICAL DESCRIPTION
• When the EGR valve (stepper motor) is actuated
from the fully closed position toward the open
position while the engine is running, EGR gas
flows.
• The ECM checks how the EGR gas flow signal
changes.
.
DESCRIPTIONS OF MONITOR METHODS
Small manifold pressure change during exhaust gas
recirculation (EGR) operation from closed to
open.
.
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)
• EGR stepper motor monitor
Sensor (The sensor below is determined to be
normal)
• Mass airflow sensor
• Engine coolant temperature sensor
• Intake air temperature sensor
• Barometric pressure sensor
• Accelerator pedal position sensor
• Manifold absolute pressure sensor
.
MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS
TSB Revision
MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>
13A-400
DTC SET CONDITIONS
Logic Flow Chart
.
Check Conditions
• At least 20 seconds have passed since the last
monitor was complete.
• Engine coolant temperature is higher than 76°C
(169
°F).
• Engine speed is at between 1,125 and 2,500
r/min.
• Intake air temperature is higher than −10°C
(14
°F).
• Barometric pressure is higher than 76 kPa (22.4
in.Hg).
• Fuel is being shut off.
• Vehicle speed is 30 km/h (19 mph) or more.
• At least 90 seconds have passed since manifold
absolute pressure sensor output voltage fluctu-
ated 1.5 volts or more.
• Battery positive voltage is higher than 10.3 volts.
• Accelerator pedal is closed.
• Volumetric efficiency is lower than 24 percent.
Start
End
No
No
No
Yes
Yes
Yes
Malfunction
Good
Monitoring
conditions
Measure manifold
pressure (P1)
Measure manifold
pressure (P2)
EGR valve open
P2 - P1 < P0 *
Specified
times
AK604336
P0 : Threshold value
MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS
TSB Revision
MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>
13A-401
• The ECM monitors for this condition for 3 cycles
of 1.8 seconds each during the drive cycle.
Judgement Criterion
• When the EGR valve opens to the prescribed
opening, when intake manifold pressure fluctua-
tion width is lower than 2.5 kPa (0.74 in.Hg).
.
OBD-II DRIVE CYCLE PATTERN
Refer to Diagnostic Function
− OBD-II Drive Cycle −
Pattern 3
.
.
TROUBLESHOOTING HINTS (The most
likely causes for this code to be set are: )
• Contaminated EGR valve and EGR passage.
• ECM failed
DIAGNOSIS
STEP 1. Check the EGR system
Refer to GROUP 17, Emission Control System
− Exhaust Gas
Recirculation (EGR) System
− General Information
Q: Are there any abnormalities?
YES : Repair it. Then go to Step 3.
NO : Go to Step 2.
STEP 2. Check the EGR valve contamination and the EGR
passage contamination.
Q: Are the EGR valve and the EGR passage clogged?
YES : Repair the EGR valve and the EGR passage
contamination.
NO : Go to Step 3.
STEP 3. 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 3
(2) Check the diagnostic trouble code (DTC).
Q: Is DTC P0401 set?
YES : Retry the troubleshooting.
NO : The inspection is complete.
DTC P0420: Warm Up Catalyst Efficiency Below Threshold
.
TECHNICAL DESCRIPTION
• The signal from the heated oxygen sensor (rear)
differs from the linear air-fuel ratio sensor,
because the catalytic converter purifies exhaust
gas. When the catalytic converter has deterio-
rated, the signal from the linear air-fuel ratio sen-
sor becomes similar to the heated oxygen sensor
(rear).
• The ECM compares the output of the linear
air-fuel ratio sensor and heated oxygen sensor
(rear) signals.
.
DESCRIPTIONS OF MONITOR METHODS
Linear air-fuel ratio sensor and heated oxygen sen-
sor (rear) rich/lean switching frequencies are
nearly equal.
.
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)
• Linear air-fuel ratio sensor monitor
MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS
TSB Revision
MULTIPORT FUEL INJECTION (MFI) <2.4L ENGINE>
13A-402
• Heated oxygen sensor (rear) monitor
• Linear air-fuel ratio sensor heater monitor
• Heated oxygen sensor (rear) heater monitor
• Heated oxygen sensor offset voltage monitor
• Misfire monitor
• Fuel system monitor
• Heated oxygen sensor (rear) feedback control
system
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
• Accelerator pedal position sensor
.
DTC SET CONDITIONS
Logic Flow Chart
.
Check Conditions
• Engine speed is lower than 3,000 r/min.
• Accelerator pedal is depressed.
• Mass airflow is between 10 and 45 g/sec.
• More than 3 seconds have elapsed after the
above-mentioned three conditions have been
met.
• Intake air temperature is higher than −10°C
(14
°F).
• Barometric pressure is higher than 76 kPa (22.4
in.Hg).
• Under the closed loop air/fuel ratio control.
• Vehicle speed is 1.5 km/h (1.0 mph) or more.
• The ECM monitors the maximum 3 times per
drive cycle under these conditions.
• Short-term fuel trim is higher than −25 percent
and lower than +25 percent.
• The cumulative mass airflow is higher than 1,741
g.
• The linear air-fuel ratio sensor rich/lean switching
frequency is more than 8 times.
Judgement Criterion
• When the monitoring for 10 seconds is carried
out 5 times, the frequency ratio of heated oxygen
sensor (rear) and linear air-fuel ratio sensor sig-
nals is the specified value or more.
NOTE: The specified value varies depending on
the average air flow rate.
.
Start
Monitoring
conditions
Malfunction
Good
End
No
No
Yes
Yes
Rf > R0
Calculate average frequency
ratio (Rf = Fr/Ff) of specified times
R0: Average threshold value
AK604337
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