Mitsubishi Galant 9G. Manual — part 1109
MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS
TSB Revision
MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>
13B-736
LOGIC FLOW CHARTS (Monitor Sequence)
.
DTC SET CONDITIONS
Check Conditions
• Throttle valve is closed.
• Vehicle speed is 1.5 km/h (0.93 mph) or less.
START
YES
NO
NO
OFF-IDLING CONDITION
IDLING CONDITION?
F1 = 0
END
NO
NO
YES
YES
MALFUNCTION
F1 > 20
SPECIFIED TIMES
MONITORED
FTPS OUTPUT
VOLTAGE > 0.2V
FLUCTUATION
NO
YES
YES
F1 = F1 + 1
GOOD
YES
NO
OFF-IDLING CONDITION
AC306647
RATIONALITY - NOISE
MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS
TSB Revision
MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>
13B-737
Judgment Criteria
• If the voltage signal from the fuel tank differential
pressure sensor changes by 0.2 volt or more,
DTC P0451 will set. The code may also set if a
sudden pressure fluctuation occurs twenty times
while the engine is idling, and then four consecu-
tive times during normal driving.
NOTE: If the number of sudden pressure fluctua-
tions does not reach twenty during any one
period of engine idling, or if the ignition switch is
turned OFF, the counter will reset to zero.
NOTE: The conditions for deviating from idling
operation are as follows:
.
•
Vehicle speed is 50 km/h (31 mph) or greater.
.
OBD-ll DRIVE CYCLE PATTERN
Refer to Diagnostic Function
− OBD-ll Drive Cycle −
Procedure 1
− Evaporative Emission System Leak
.
.
TROUBLESHOOTING HINTS (THE MOST
LIKELY CAUSES FOR THIS CODE TO BE
SET ARE:)
• Malfunction of the fuel tank differential pressure
sensor.
• A damaged harness in the fuel tank differential
pressure sensor circuit.
• Malfunction of the PCM.
.
OVERVIEW OF TROUBLESHOOTING
• DTC P0451 can be set by a faulty fuel tank differ-
ential pressure sensor or related circuit, or PCM
failure.
• To check for system blockage, do a performance
test which uses a mechanical vacuum gauge and
scan tool MB991958 set on the fuel tank differen-
tial pressure sensor (TANK PRS SNSR 73). The
mechanical gauge reading is used to verify scan
tool MB991958 reading. A comparison of the
mechanical gauge with the reading on scan tool
MB991958 will locate a problem in the system.
MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS
TSB Revision
MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>
13B-738
DIAGNOSIS
Required Special Tools:
• MB991958: Scan Tool (MUT-III Sub Assembly)
• MB991824: V.C.I.
• MB991827: MUT-III USB Cable
• MB991910: MUT-III Main Harness A
• MB991658: Test Harness Set
• MB991923: Power Plant ECU Check Harness
STEP 1. Using scan tool MB991958, check data list item 73:
Fuel Tank Differential Pressure Sensor.
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) Disconnect hose H from the evaporative emission canister,
and plug the hose.
(3) Turn the ignition switch to the "ON" position.
(4) Remove the fuel cap.
(5) Set scan tool MB991958 to the data reading mode.
• Item 73, Fuel Tank Differential Pressure Sensor.
• The fuel tank pressure reading on the scan tool
should be
−1.5 to 1.5 kPa (−0.443 to 0.443 inHg).
AC305412
AB
MB991910
DATA LINK
CONNECTOR
MB991824
MB991827
AC306778
AC
HOSE H
PLUG
MULTIPORT FUEL INJECTION (MFI) DIAGNOSIS
TSB Revision
MULTIPORT FUEL INJECTION (MFI) <3.8L ENGINE>
13B-739
(6) Connect the evaporative emission system pressure pump
(Miller number 6872A) to the fuel tank filler tube by using
fuel tank adapter (MLR-8382) and pressurize the fuel tank.
• The fuel tank pressure reading should increase.
(7) Turn the ignition switch to the "LOCK" (OFF) position. Then
disconnect scan tool MB991958.
(8) Remove the evaporative emission system pressure pump
(Miller number 6872A) and the fuel tank adapter
(MLR-8382), and reinstall the fuel cap.
(9) Connect hose H to the evaporative emission canister.
Q: Is the fuel tank pressure between
−1.5 and 1.5 kPa
(
−0.443 and 0.443 inHg)?
YES : 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
). Go to
Step 17.
NO : Go to Step 2.
STEP 2. Measure the sensor output voltage at PCM
connector B-20 by using check harness special tool
MB991923.
(1) Disconnect all the connectors from the PCM.
AC306661
AC306248
B-20 HARNESS
CONNECTOR:
COMPONENT SIDE
AB
B-20
CONNECTOR: B-20
PCM
AIR
CLEANER
Нет комментариевНе стесняйтесь поделиться с нами вашим ценным мнением.
Текст