Page 46 of 241

GENERAL DESCRIPTION
ENGINE MECHANICAL11A-2
GENERAL DESCRIPTIONM2112000101162
This model is equipped with a newly developed 4B11
engine. It is a 4-cylinder, double overhead camshaft
(DOHC) engine with a 2.0-L cylinder displacement.
This engine has adopted the following features:
•MIVEC (MITSUBISHI INNOVATIVE VALVE TIM-
ING ELECTRONIC CONTROL SYSTEM) for
both the intake and exhaust valves
•Cylinder block made of an aluminum alloy
•Valve train with direct-acting valve tappets
•Silent timing chain
MAIN SPECIFICATIONS
DescriptionsSpecifications
Engine type4B11
Bore × stroke mm (in)86 (3.4) × 86 (3.4)
Total displacement cm3 (cu in)1,998 (121.9)
Combustion chamberPent-roof type
Number of cylinders4
Valve mechanismTy p eDOHC
Intake valve8
Exhaust valve8
Compression ratio10.0
Va l v e t i m i n gIntake valveOpens (BTDC)3° − 28°
0° − 25°
Closes (ABDC)45° − 20°
48° − 23°
Exhaust valveOpens (BBDC)41° − 21°
44° − 24°
Closes (ATDC)3° − 23°
0° − 20°
Maximum output kW/r/min (HP/r/min)107/6,000 (143/6,000)
113/6,000 (152/6,000)
Maximum torque N⋅m/r/min (lbs-ft/r/min)194/4,250 (143/4,250)
198/4,250 (146/4,250)
Fuel injection system typeElectronic control MPI
Ignition system typeElectronic spark-advance control type (4-coil
type)
Generator typeAlternating current system (with built-in IC
regulator)
Starter motor typeReduction drive type
Page 49 of 241
BASE ENGINE
ENGINE MECHANICAL11A-5
CYLINDER BLOCK
A cylinder block made of an aluminum alloy has
been adopted for weight reduction.
5 bearings are used for the crankshaft journals and
the No. 3 bearing sustains the thrust load of the
crankshaft.
The water jacket is the full Siamese type.
An oil jet is used in front of the cylinder block to sup-
ply engine oil to the timing chain.
AK502486
Oil jetCylinder blockBearing cap
AE
Ladderframe
ITEMSPECIFICATIONS
Distance between top and
crankshaft center mm (in)230.1 (9.06)
Bore mm (in)86 (3.4)
Bore pitch mm (in)96 (3.8)
Stroke mm (in)86 (3.4)
Page 58 of 241
BASE ENGINE
ENGINE MECHANICAL11A-14
VALVE TAPPETS
To adjust the valve lift, 47 sizes of valve tappets are
available in 0.015 mm (0.0006 in) increments, from
3.000 mm (0.1181 inch) to 3.690 mm (0.1453 in).
MIVEC (MITSUBISHI INNOVATIVE VALVE TIMING ELECTRONIC CONTROL SYSTEM)
The MIVEC consists of the parts shown in the illus-
tration.
This system continuously varies and optimally con-
trols the opening and closing timing of the individual
intake and exhaust valves, in order to improve torque
and power output in all speed ranges.
AK502503
Identification
markThickness
AD
AK503014
Exhaust V.V.T. sprocket
Section A-ASection B-B
Engine oil control
valve filter
Intake V.V.T. sprocket
Cylinder head
Cylinder blockB
B
Engine oil
control valve
Cylinder head
Cylinder block A
A
AE
Engine oil
control valve
Page 65 of 241
AUTO-CRUISE CONTROL SYSTEM
ENGINE AND EMISSION CONTROL17-3
AC611102 AC611098
AC611099
AC611100
AC606956
AC611101
Auto-cruise
control switch
Data link connector
Hood
lock
release
handle
AD
Clutch switch
Stoplight switch
Accelerator pedal
[Built-in accelerator
pedal position sensor
(APP sensor)] Engine control
module (ECM)"CRUISE" indicator light
Transaxle control
module (TCM)
Brake pedal
assembly
Throttle body
[Built-in throttle position sensor
(TP sensor) and
throttle actuator control motor
(TAC motor)]
Transmission
range switch
Vehicle speed
sensor
Page 67 of 241

AUTO-CRUISE CONTROL SYSTEM
ENGINE AND EMISSION CONTROL17-5
CONSTRUCTION AND OPERATIONM2170002000232
SYSTEM OUTLINE
The ECM calculates the auto-cruise control system
operation status when the ECM receives input sig
-
nals from the auto-cruise control switch, vehicle
speed and cancel system [stoplight switch and clutch
switch or transmission range switch ]. The engine control section sends the target acceler
-
ator pedal opening angle value for auto-cruise con-
trol system, the TCM issues a command to transaxle
control , and the gauge issues an ON/OFF
command for the "CRUISE" indicator light.
In the engine control section, the target throttle valve
opening angle value is calculated from the target
accelerator pedal opening angle value for
auto-cruise control system and the actual accelerator
angle value.The vehicle speed is then controlled by
applying the TAC motor.
BLOCK DIAGRAM
Throttle position sensor (TP sensor)Informs the ECM of the throttle valve opening angle.
Transaxle control module (TCM) •Based on the transaxle control signal from the
ECM, it controls the transaxle.
•Outputs the signal from the secondary pulley
speed sensor to the ECM.
•Transmits the selector lever "N" position signal
from the transmission range switch to the ECM.
Vehicle speed sensor Transmits the vehicle speed signal proportional to
the vehicle speed to the ECM.
Component Function
TAC motor Target accelerator
pedal opening
angle signal
Engine control section
Cruise control section"CRUISE" indicator light
AC611103
Actual accelerator
pedal opening
angle signal
Shift control
signal
Target throttle
valve opening
angle signal
Auto-cruise control switch
ECM
Stoplight switch, clutch switch
TCM
"CRUISE"
indicator light
ON/OFF signal
APP sensor
Transmission
range switch
signal Shift control
signal
TransaxleTransmission
range switch
signal
Secondary
pulley speed
sensor signal
ON/OFF
signalON/OFF
signal
Vehicle speed
sensor
Vehicle
speed
signal
Secondary
pulley speed
sensor signal
Page 69 of 241

AUTO-CRUISE CONTROL SYSTEM
ENGINE AND EMISSION CONTROL17-7
FAIL-SAFE FUNCTION
When any of the following conditions are satisfied,
the auto-cruise control system function is stopped
until the system returns to normal. Also, when any of
the conditions are satisfied during the constant
speed driving, the constant speed driving is can
-
celled immediately.
•An abnormality occurs to the auto-cruise control
switch.
•An abnormality occurs to the stoplight switch.
When any of the following conditions are satisfied,
stop the vehicle once and turn the ignition switch to
"LOCK" (OFF). Otherwise, even when the system
returns to normal, the auto-cruise control system
function will continue to be stopped. Also, when any
of the conditions are satisfied during the constant
speed driving, the constant speed driving is can
-
celled immediately.
•ECM abnormality
•TP sensor abnormality
•APP sensor abnormality
.
DIAGNOSIS FUNCTION
•The diagnostic trouble code check is possible
with the "CRUISE" indicator light.
•To facilitate the system check, check the service
data output with the M.U.T.-III.
NOTE: For diagnostic items, service data output
items, and check method, refer to the Service Man
-
ual.
Page 75 of 241

EMISSION CONTROL
ENGINE AND EMISSION CONTROL17-13
EXHAUST GAS RECIRCULATION (EGR) VALVE
An EGR valve is installed in the EGR valve support.The EGR
valve controls EGR flow volume using the stepper motor
method and reduces exhaust gas (NOx) and fuel consumption.
The EGR valve drives the stepper motor based on the signal
from ECM. When stepper motor rotor turns in clockwise or
anti-clockwise direction, the shaft fitted with a rotor and a screw
expands and contracts and the movement of the shaft causes
the valve to go up and down. Thus, EGR path gap is controlled
minutely. The stepper motor turns 15
° per step. The stepper
motor turns forward or back only up to the angle dictated by the
number of pulse signals (number of steps) from the ECM. In
other words, increase and decrease of the EGR flow volume
depends on the number of signals (number of steps) from
ECM. ECM changes current flow to the 4 coils (A, B, C, D) in
the stepper motor in sequence according to the phase pattern
in the following chart in order to turn the stepper motor rotor.
Open valve changes phase in order of 0
→ 1 → 2 → 3 → 0. Close
valve changes phase in order of 3
→ 2 → 1 → 0 → 3.
Phase
numberStepper motor coil
Coil ACoil BCoil CCoil D
0ONOFFOFFON
1ONOFFONOFF
2OFFONONOFF
3OFFONOFFON
AK604144
Coil
Shaft
Valve Outlet
Inlet
Rotor
Magnet
AB
AK604145
From MFI relay
EGR valve
(stepper motor)
ECM Coil
ACoil
BCoil
CCoil
DFlow rate
Step
AB
Page 89 of 241
WATER PASSAGE
ENGINE COOLING14-3
WATER PASSAGEM2140004000172
NOTE: EGR: Exhaust Gas Recirculation
CVT: Continuously Variable Transmission
WAT E R P U M PM2140003000168
The water pump is the centrifugal, impeller type that
is installed in front of the cylinder block. It is driven by
the drive belt.
AK603624
Water pump
EGR
AB
Thermostat
Radiator Throttle body
CVT oil
coolerHeater
Water pump
EGR
Thermostat
Radiator Throttle body
CVT oil
cooler Heater
AK503034
Impeller
AD
ItemSpecifications
Discharge volume L/min185
Impeller diameter mm (in)62 (2.4)
Pulley outer diameter mm
(in)137 (5.4)