2000 MITSUBISHI MONTERO fuel consumption

GDI -General Information13A-3
GENERAL INFORMATION
The Gasoline Direct Injection System consists
of sensors which detect the engine conditions,
the engine-ECU or engine-A/T-ECU
which controls the system based on
signals from these sensors, and actuators
which operate under the control of the
engine-ECU or engine-A/T-ECU .The engine-ECU or engine-A/T-ECU
carries out activities such as fuel injection
control, idle speed control and ignition timing
control. In addition, the engine-ECU or
engine-A/T-ECU is equipped with several
diagnosis modes which simplify troubleshooting
when a problem develops.
FUEL INJECTION CONTROL
The injector drive times and injector timing are
controlled so that the optimum air/fuel mixture
is supplied to the engine to correspond to the
continually-changing engine operation condi-
tions.
A single injector for each cylinder is mounted
at the cylinder head. The fuel is sent under
pressure from the fuel tank to the fuel pressure
regulator (low pressure) by the fuel pump (low
pressure). The pressure is regulated by the
fuel pressure regulator (low pressure) and the
fuel regulated is then sent to the fuel pump
(high pressure). The fuel under increased
pressure generated by the fuel pump (high
pressure) is then regulated by the fuel pressure
regulator (high pressure) and is then distributed
to each of the injectors via the delivery pipes.Fuel injection is normally carried out once for
each cylinder for every two rotations of the
crankshaft. The firing order is 1-2-3-4-5-6. This
is called sequential fuel injection.
When the engine is cold or under a severe
load, the “open-loop” control keeps the air/fuel
ratio at a richer than usual level to maintain
driveability. When the engine is under low or
medium loads, the air/fuel ratio becomes leaner
to reduce fuel consumption. When the engine
is running at medium or high loads after having
warmed up, the “closed-loop” control uses the
signal from the oxygen sensor to keep the
air/fuel ratio at the optimum theoretical level.
THROTTLE VALVE OPENING ANGLE CONTROL
This system controls throttle valve opening
angle electronically. The engine-ECU
or engine-A/T-ECU determines how
deeply the accelerator pedal is depressed by
means of the accelerator position sensor (APS).
Then the engine-ECU or engine-A/T-ECU sends a target value of the
throttle valve opening angle to the throttle valve
controller. The throttle valve control servo
operates the throttle valve so that it reaches
the target opening angle.
IDLE SPEED CONTROL
This system maintains engine idle speed at
a predetermined condition by controlling the
air flow that passes through the throttle valve
according to engine idling condition and engine
loads at idling.
The engine-ECU or engine-A/T-ECU
operates the throttle valve control servoso that engine speed is maintained within a
map value. The map value is predetermined
according to engine coolant temperature and
air-conditioning load.
IGNITION TIMING CONTROL
The power transistor located in the ignition
primary circuit turns ON and OFF to control
the primary current flow to the ignition coil. This
controls the ignition timing in order to provide
the optimum ignition timing with respect to the
engine operating conditions. The ignition timingis determined by the engine-ECU or
engine-A/T-ECU from the engine speed,
intake air volume, engine coolant temperature,
atmospheric pressure and injection timing
(intake stroke or compression stroke).


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CHASSIS ELECTRICAL -Clock or Center Display54A-54
BEFORE REMOVING THE BATTERY
The Center display has a large amount of data unique to the vehicle in its memory. When the battery
cable is disconnected, that memory is affected as shown in the table below. Accordingly, it is necessary
to make sure that you take notes of important information before disconnecting the battery cable.
FunctionInput function/memoryWhen battery cable is disconnected
Clock set on displayCurrent timeRetains data for approx. 1 hour
Vehicle model setShort (3-door models)/long (5-door
models)Retains data for approx. 1 hour
Brightness set for displayPosition set on displayRetains data for approx. 1 hour
Unit set for trip computerkm or mile, L/100km or mpg or km/L
Average vehicle speed after resetRetains data for approx. 1 hour
Average vehicle speed on displayAverage vehicle speed after resetRetains data for approx. 1 hour
Average fuel consumption on displayAverage fuel consumption after resetRetains data for approx. 1 hour
Cruising range on displayCruising range, fuel economyRetains data for approx. 1 hour
Outside temperature on displayOutside temperature after the ignition
switch is turned to the OFF(LOCK)
position.Retains data for approx. 1 hour
* The outside temperature sensor
is located near the engine.
Therefore, incorrectly high
temperature may be displayed
when the battery cable is
reconnected within one hour.
DIAGNOSIS FUNCTION FOR CENTER DISPLAY
Center display has the following diagnosis function:
FunctionContents
Service functionThere are the following 4 diagnosis modes available
1. Check of vehicle informationThe vehicle, short (3-door models)/long (5-door models) set
2. Check of LCD segmentsThe LCD segments for display available to light on or not
3. Check of sensorsOutside temperature, voltage of fuel gauge unit, system voltage, fuel amount
remains, fuel economy calculated after supply of fuel
4. Check of units connected into
the center displayThe units connected on display
Voltage (%) on terminal for MUT-II
Vehicle speed signal sent by engine-ECU
Oscillating signal


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CHASSIS ELECTRICAL -Clock or Center Display54A-60
Terminal
No.Input/
OutputSignal symbolTerminal
voltage (V)Wiring harness
problemTrouble symptom caused by wiring
harness problem
Open
circuitShort
circuit
15Input/
OutputKHi: System
voltage
Lo: 0-1ExistsExistsValues on trip information screen (average
vehicle speed, fuel consumption and
cruising distance) are abnormal. Commu-
nication is impossible between the
engine-ECU and the MUT-II.
16------
17Input/
OutputM-BUSY
(AUDIO)Hi: 4-5
Lo: 0-1ExistsExistsAudio display does not appear. Panel
switch cannot be operated for audio unit.
Nighttime illumination does not appear for
audio unit.
18-SHIELD-GND----
19Input/
OutputM-BUSY
(A/C)Hi: 4-5
Lo: 0-1ExistsExistsA/C display does not appear.
Outside air temperature does not appear
20-SHIELD-GND----
21, 22------
23InputEX-TEMPExistsExistsOutside air temperature does not appear.
24InputILL+Hi: System
voltageExists-Nighttime illumination does not appear for
audio units.
Lo: 0-1
-ExistsBlown multipurpose fuse.
25InputACC (ACCSystem volt-Exists-Screen display does not appear.
power supply)age
-ExistsBlown multipurpose fuse.
26Input+BSystem volt-Exists-Screen display does not appear.
age
-ExistsBlown multipurpose fuse.
27InputVSSHi: System
voltage
Lo: 0-1ExistsExistsAbnormal outside air temperature ap-
pears.
(only diesel-powered vehicles)
28-GND (earth)-Exists-Screen display does not appear.
29, 30------
31-GND-TEMPExistsExistsOutside air temperature does not appear.
32InputILL -ExistsExistsThe display screen can not be dimmed.
33InputFUEL GAUGE-ExistsAbnormal cruising distance appears.
34, 35------
36InputIG1Hi: System
voltageExists-Communication with engine-ECU is im-
possible. Abnormal driving data values
appear.
-ExistsCommunication with engine-ECU is im-
possible. Abnormal driving data values
appear. Blown multipurpose fuse.


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CHASSIS ELECTRICAL -Clock or Center Display54A-61
INSPECTION CHART CLASSIFIED BY TROUBLE SYMPTOMS
Related unitTrouble SymptomInspection pro-
cedure No.Reference
page
Malfunction of center
display, related sen-No display appears after the ignition key is turned to the
ACC position.154A-62
sors, and wiring har-
nesses
Outside air temperature does not appear or abnormal
outside air temperature appears.254A-62
Abnormal vehicle speed is displayed on the service
mode.354A-63
Abnormal driving data are displayed:
D
Abnormal average fuel consumption (momentary
fuel consumption) and average vehicle speed
D
Abnormal cruising distance454A-64
Clock runs fast or slow.554A-64
The display screen is dim.654A-65
Air conditioning display does not apper.754A-66


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CHASSIS ELECTRICAL -Clock or Center Display54A-64
INSPECTION PROCEDURE 4
Abnormal driving data are displayed:
DAbnormal average fuel consumption (momentary fuel consumption) and average vehicle speed
DAbnormal cruising distance
Are the average fuel consumption and average vehicle speed dis-
play correctly?NOGo to inspection procedure 3.1.
YES
Does the vehicle information on displayed on the screen meet
with the actual vehicle?
Is the vehicle type (long or short body) recognized correctly?
(Select “Check of units connected into the center display” and
“Check of vehicle information” on the service mode.)NOReplace the center display unit.
YES
Is remained fuel amount displayed correctly on servicemode?YESEnd (no abnormality).
NO
Measure at center display unit connector D-03.
DDisconnect the connector.
DVoltage between terminal 33 and body earth.
OK:0.1 - 3 VNGCheck the wiring harness between center display unit and the
fuel gauge unit, and repair ifnecessary. (relevant units: Combination
meter, fuel gauge unit)
OK
Replace the center display unit.
NOTE
(1) If the remained fuel amount is so small that the fuel gauge unit can not detect a correct amount,
incorrect cruising range may be displayed.
(2) Fuel consumption is updated each time fuel is supplied. Furthermore, the cruising range depends
on road and driving conditions.
INSPECTION PROCEDURE 5
Clock runs fast or slow.
NGRepair the fuse and wiring harness.
OK
YES
Does it receive a radio station on differ-
ent region where has timelag?YESTurn off the CT function.
NO
Replace the center display unit.
Measure at center display unit connec-
tor D-03.
DIgnition switch: OFF
DVoltage between terminal 26 and
body earth.
OK:System voltage
Is the symbol “CT” displayed?
NO


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