2000 MITSUBISHI MONTERO egr valve

GDI -Troubleshooting 13A-185
Inspection procedure 18
Too high CO and HC concentration when idling
Probable cause
Abnormal air-fuel ratio is suspected.DMalfunction of the air/fuel ratio control system
DDeteriorated catalyst
OK
To the nextpage
NG
Replace the ignition coil.
OK
Check ignition coil spark for each cylinder.
1. Remove the ignition coil.
2. Install a new sparkplug to the removed ignitioncoil.
3. Disconnect the injector intermediate connector.
Caution
Never touch the connector terminal as approx. 100 V is applied to the injector, or you are seriously injured.
4. Earth the sparkplug electrodesecurely.
5. Check that the sparkplug igniteswhen theengine iscranked.NG
NG
Measure fuel high -pressure between the fuelpump (high
pressure) and injector. (Refer to P.13A-223.)
Check the trouble symptoms.
OK
MUT-
IIData list
11 Oxygen sensor (Refer to P.13A-198.)
OK:
Repeat 0 - 400 mV and 600 - 1,000 mV alternately
during idling(wait for at least 2 minutes after the
enginestarted to run at idle).OKReplace the oxygen sensor.
OK
MUT-
IIData list
11 Oxygen sensor (Refer to P.13A-198.)
OK:
600 - 1,000 mV when theengine is suddenlyracedNGCheck the oxygen sensor system. (Refer to P.13A-131, code
No.11.)
OK
MUT-
IIActuator Test
08 Purge control solenoid valve
(Refer to P.13A-203.)NGCheck the purge control solenoid valve system
(Refer to P.13A-197, Inspection procedure 36.)
OK
MUT-
IIData list
68 EGR valve (Refer to P.13A-198.)NGCheck the EGR valve system (Refer to P.13A-196, Inspection
procedure 35.)
OK
MUT-
IIData list
25 Barometric pressure sensor (Refer to P.13A-198.)NGCheck the barometric pressure sensor system (Refer to
P.13A-145, code No.25.)
OK
MUT-
IIData list
13 Intake air temperature sensor (Refer to P.13A-198.)NGCheck the intake air temperature sensor system (Refer to
P.13A-135, code No.13.)
OK
MUT-
IIData list
21 Engine coolant temperature sensor (Refer to P.13A-198.)NGCheck theengine coolant temperaturesensor system (Refer
to P.13A-138, code No.21.)
NO
Check the ignition timing. (Refer to GROUP 11A - Engine
Adjustment.)NGCheck that the crankanglesensor andtiming beltcover are
properly installed.
MUT-
IISelf-Diag Code
Are diagnosis codes displayed?YESRefer to P.13A-130, INSPECTION CHART FOR DIAGNOSIS
CODES.


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GDI -Troubleshooting 13A-196
Inspection procedure 34
Injector driver
Probable cause
The engine-A/T-ECU drives the injector by the drive signal.DMalfunction of the injector driver
DImproper connector contact,opencircuit or
short-circuited harness wire
DMalfunction of the engine-A/T-ECU
OK
NG
Replace the engine-A/T-ECU.
OK
Check the trouble symptoms.Transient malfunction
(Refer to GROUP 00 - Points to Note for Intermittent
Malfunctions.) OK
Use a analyzer to measure the signal waveform at the engine-
A/T-ECU connectors D-119 and D-120.
DEngine: idling
DSelector lever position: P
DVoltage between 96 and earth, and between 1 and earth
OK:
A normal waveform should be displayed as described
on P.13A-214 (INSPECTIONPROCEDURE USING
AN ANALYZER).NGReplace the injector driver.
NGCheck the following connectors:
B-121, D-119Repair
NG
Repair
OK
Check the harness wire between the injector driver and engine-
A/T-ECU.
Inspection procedure 35
EGR valve (stepper motor) system
Probable cause
The engine-A/T-ECU controls the EGR valve (stepper motor) in order to control
the amount ofexhaust gas mixed in the intake air.DMalfunction of the EGR valve
DOpen circuit or short-circuited harness wire in the
EGR valve circuit
DMalfunction of the engine-A/T-ECU
OK
Check the trouble symptoms.NGCheck the harness wire between the
engine controlrelay and the EGR valve,
and repair if necessary.
OK
Check the trouble symptoms.NGCheck the harness wire between the
engine-A/T-ECU and EGR valve, and
repair if necessary.
OK
Check the trouble symptoms.NGReplace the engine-A/T-ECU.
OK
Check the following connector:
D-120NG
Repair
OK
Measure at the engine-A/T-ECU con-
nector D-120.
DDisconnect the connector, and
measure at the harness side.
DVoltage between 51, 53, 60, 62
and earth (Ignition switch: ON)
OK:
System voltageNGCheck the following connector:
B-60NG
Repair
OK
Measure at the EGR valve connector
B-60.
DDisconnect the connector, and
measure at the harness side.
DVoltage between 2, 5 and earth
(Ignition switch: ON)
OK:
System voltageNGCheck the following connector:
B-25XNG
Repair
Check the EGR valve. (Refer to GROUP
17 - Emission Control System.)NG
Replace


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GDI -Troubleshooting 13A-201
Item
No.Reference
page Inspection
procedure
No. Normal condition Inspection contents Inspection
item
41Injector
drive time*1D
Engine: CrankingWhen engine coolant
temperature is 0_
C120 - 160 msCode No.
4113A-147
When engine coolant
temperature is 20_
C70 - 90 ms
When engine coolant
temperature is 80_
C20 - 35 ms
Injector
drive time*2D
Engine coolant
temperature: 85 -
95_
CIdling0.3 - 0.8 ms
95_
C
D
Lamps and all
accessories: OFF
D
Transmission:
2,500 r/min0.4 - 1.0 ms
D
Transmission:
P range
D
Within six minutes
after engine start-
ing
When engine is sud-
denly racedIncreases
44Ignition ad-
vance valueD
Engine: After hav-
ing warmed up
D
Timing lamp is set.
(The timing lamp is
set in order toIdling12 - 28_
BTDCCode No.
4413A-148
set in order to
check actual igni-
tion timing.)
D
Within six minutes
after engine start-
ing
2,500 r/min15 - 35_
BTDC
49A/C relayEngine: After having
warmed up, idlingA/C switch: OFFOFF (compressor
clutch is not oper-
ating)Procedure
No.3113A-194
A/C switch: ONON (compressor
clutch is operat-
ing)
67Stop lamp
switchIgnition switch: ONBrake pedal: De-
pressedOFFProcedure
No.3213A-195
Brake pedal: Re-
leasedON
68EGR valveD
Engine coolant
temperature: 85 -
95_
CIdling2 - 20 STEPProcedure
No.3513A-196
D
Lamps and all
accessories: OFF
D
Transmission: P
range
2,500 r/min0 - 10 STEP
74Fuel pres-
sure sensorD
Engine coolant
temperature: 85 -
95_
CEngine: Cranking2 MPa or moreCode No.
5613A-151
D
Lamps and all
accessories: OFF
D
Transmission: P
range
Engine: Idling4.0 - 6.9 MPa


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GDI -Troubleshooting 13A-206
Terminal
No.Normal condition Check condition (Engine condition) Check item
49Engine control relayIgnition switch: OFF0-3V
Ignition switch: ONSystem voltage
51EGR valve (A)Ignition switch: OFF to ON5-8V
53EGR valve (C)
(Repeatedly changes
for approx. 3 seconds)
60EGR valve (B)
62EGR valve (C)
52Power steering fluid
pressure switchEngine: Idling after
warming-upWhen steering wheel is
stationarySystem voltage
When steering wheel is
turned0-3V
55Barometric pressureIgnition switch: ONAt an altitude of 0 m3.7 - 4.3 V
sensor
At an altitude of 1,200 m3.2 - 3.8 V
56Camshaft position sen-Engine: Cranking0.4 - 3.0 V
sor
Engine: Idling0.5 - 2.0 V
58Ignition switch-STEngine: Cranking8 V or more
61A/C switch 2Refer to GROUP 55 - Troubleshooting (Check at A/C-ECU or Engine-ECU
Terminal).
63Injector open circuit
check signalEngine: Increases from idling up to 4,000 r/minThe voltage decreases
slightly (approx. 0.7 V)
from 4.5 - 5.0 V.
64Intake air temperature
sensorIgnition switch: ONWhen intake air tempera-
ture is 0_C3.2 - 3.8 V
When intake air tempera-
ture is 20_C2.3 - 2.9 V
When intake air tempera-
ture is 40_C1.5 - 2.1 V
When intake air tempera-
ture is 80_C0.4 - 1.0 V
65Air flow sensorEngine: Idling2.2 - 3.2 V
Engine speed: 2,500 r/min
66Backup power supplyIgnition switch: OFFSystem voltage
71Oxygen sensorEngine: Running at 2,500 r/min after warming-up
(Check by using a digital voltmeter.)Voltages of 0 V and 0.8
V alternate


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DIESEL FUEL <4M4> -General Information13C-2
GENERAL INFORMATION
The electronically-controlled fuel injection system consists of sensors which detect the condition of the
diesel engine, an engine-ECU which controls the system based on signals from these sensors, and actuators
which operate according to control commands from the engine-ECU.
The engine-ECU carries out operations such as fuel injection rate control, fuel injection timing control
and idle up control. In addition, the engine-ECU is equipped with several self-diagnosis functions which
make troubleshooting easier in the event that a problem develops.
FUEL INJECTION RATE CONTROL
The fuel injection completion timing is controlled by means of a solenoid-type spill valve to ensure that
the optimum amount of fuel is supplied to the engine in accordance with gradual changes in the engine
running condition.
Before fuel injection starts, the solenoid-type spill valve is on (energized), so that the valve is closed.
As the plunger turns and rises, fuel is sent out under pressure, and when the fuel flow rate reaches
the target value for fuel injection, the solenoid-type spill valve turns off. When the solenoid-type spill
valve turns off, the fuel under high pressure inside the plunger is leaked out into the pump chamber
and fuel injection is completed.
FUEL INJECTION TIMING CONTROL
The position of the injection pump timer piston is controlled so that fuel injection is carried out at the
optimum timing in accordance with the engine running condition.
The timer piston position is determined by duty control of the timing control solenoid valve which is located
in the line between the high-pressure chamber and the low-pressure chamber of the timer piston.
The fuel injection timing is advanced by increasing the control duty of the timing control solenoid valve.
IDLE SPEED CONTROL
Controlling the fuel injection rate in accordance with the engine running condition maintains the idle speed
at the optimum condition.
SELF-DIAGNOSIS FUNCTION
DWhen an abnormality is detected in any of the sensors or actuators, the engine warning lamp illuminates
to warn the driver.
DWhen an abnormality is detected in any of the sensors or actuators, a diagnosis code number
corresponding to the problem which occurred is output.
DThe RAM data relating to the sensors and actuators which is stored in the engine-ECU can be read
using the MUT-II. In addition, the actuators can be force-driven under certain conditions.
OTHER CONTROL FUNCTIONS
1. Power Supply Control
When the ignition switch is turned to ON, the relay turns on and power is supplied to components
such as the timing control solenoid valve.
2. Intake Air Throttle Control
When the engine is idling after having warmed up, the throttle valve is half opened to restrict the
amount of intake air in order to reduce vibration and noise.
3. A/C Relay Control
Turns the compressor clutch of the A/C ON and OFF
4. Fan motor relay control
The radiator fan and condenser fan operating speeds are controlled in accordance with the engine
coolant temperature and the vehicle speed.
5. Glow Control
Refer to GROUP 16.
6. EGR Control
Refer to GROUP 17.


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DIESEL FUEL <4M4> -Troubleshooting13C-6
FAIL-SAFE, BACKUP FUNCTIONS
When abnormalities in the major sensors are detected by diagnosis functions, pre-set control logic operates
to maintain a safe driving condition for the vehicle.
Diagnosis itemControl features in malfunction
Accelerator pedal position sensorD
Accelerator pedal released (idle switch ON)
Acceleration opening degree = 0%
D
Accelerator pedal applied (idle switchOFF)
Engine controlled at low speed
Acceleration opening degree = 20% fixed
Idle switchD
Void idling speed control.
D
Void cruise control.
Engine speed sensorD
Engine controlled at low speed
D
Void cruise control.
Boost air temperature sensorMaintain the intake air temperature at 50_
C.
Vehicle speed sensorD
Void idling speed control.
D
Void cruise control.
Engine coolant temperature sensorMaintain the engine coolant temperature at 80_
C.
Control sleeve position sensorD
Engine controlled at low speed
D
Void cruise control.
Timer piston position sensorD
Injection timing stabilizing control
D
Void cruise control.
Barometric pressure sensor (ECU
built-in)Keep the barometric pressure at 101 kPa.
Fuel temperature sensorMaintain the fuel temperature at 50_
C.
Boost pressure sensorKeep the boost pressure as barometric pressure (101 kPa).
Injection correction ROMVoid correction.
GE actuatorD
Engine controlled at low speed
D
Void cruise control.
Over boostVoid cruise control.
Timing control valveD
Injection timing stabilizing control
D
Void cruise control.


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DIESEL FUEL <4M4> -Troubleshooting13C-19
Code No. 41 Main throttle solenoid valve systemProbable cause
Range of Check
DEngine speed is 1600 r/min or higher and the accelerationopening degree is
60% or more.
Set Conditions
DBoost pressure is lower than barometric pressure + 30 kPa for two seconds.
Range of Check
DWith the idlingspeed controlled, theengine warmed up, and no failure found
Set Conditions
DBoost pressure is higher than barometric pressure - 2.7 kPa for 3 seconds.DMain throttle solenoidvalve inoperative
DMain throttle solenoidvalveopencircuit, short
circuit, or connector contact inoperative
DEngine-ECU inoperative
OK
Check the following connector:
B-45NG
Repair
OK
OK
Check and repair the harness between the
control relay and the solenoid valve
connector.
Main throttle solenoidvalve check (Refer to
P.13C-48.)
Check the trouble symptoms.
Replace the engine-ECU.
NG
OK
RepairCheck the following connector:
D-110
Check the trouble symptoms.NGReplace
NG NG
Check the following connectors:
B-45, B-45-2NG
Repair
OK
Check and repair the harness between the
control relay and the solenoid valve
connector.
Check the trouble symptoms.
NG
NGMeasure at D-110 engine-ECU connector
DDisconnect the connector and measure at
the harness side.
DVoltage between 14 and the earth
(Ignition switch: ON)
OK:
System voltageOK
Measure at B-45-2 main throttle solenoid
valve connector
DDisconnect the connector and measure at
the harness side.
DVoltage between 1 and the earth
(Ignition switch: ON)
OK:
System voltage


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DIESEL FUEL <4M4> -Troubleshooting13C-28
Inspection procedure 11
Idling instable (rough idling, hunting)
Probable cause
Probable causes can be found in troubles with control system, injectionpump,
fuel system, glow system, intake system, and EGR system.DControl system inoperative
DInjection pump inoperative
DFuel system inoperative
DIntake system inoperative
DGlow system inoperative
DEGR system inoperative
DEngine-ECU inoperative
NG
Repair
MUT-
IISelf-Diag code
Is a diagnosis code output?YESInspection chart for diagnosis codes (Refer to P.13C-7.)
NO
Conduct MUT-IIData list check and an actuator test. (Refer
to P.13C-32, 37.)OKInspect the following items in order:
DGlow plug, glowplugrelay
DEGR system
DInjection nozzle
DCompression pressure
DValve clearance
DThrottle body assembly
DInjection timing
DFuel line bleeding
DInjection pump
Inspection procedure 12
The engine stalls after running for a while.
Probable cause
Probable causes can be found in troubles with control system, injectionpump,
fuel system, and intake system.DControl system inoperative
DInjection pump inoperative
DFuel system inoperative
DIntake system inoperative
DEngine-ECU inoperative
NG
Repair
MUT-
IISelf-Diag code
Is a diagnosis code output?YESInspection chart for diagnosis codes (Refer to P.13C-7.)
NO
Conduct MUT-IIData list check and an actuator test. (Refer
to P.13C-32, 37.)OKInspect the following items in order:
DThrottle body assembly
DFuel filter
DInjection pump


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