Page 529 of 4770
50ENGINEÐ1MZ±FE ENGINE
3. Engine Control System Diagram
*: Only for the
Automatic Trans-
axle Models
Page 530 of 4770
51 ENGINEÐ1MZ±FE ENGINE
4. Layout of Components
Page 531 of 4770
52ENGINEÐ1MZ±FE ENGINE
5. Main Components of Engine Control System
Mass Air Flow Meter
The hot wire type mass air flow meter has been
changed to the plug±in type. Its basic operation is the
same as that of the previous type.
6. EGR Control
In the previous models, an EGR vacuum modulator or a VSV was used to control the EGR gas volume. In the new
model, the ECM regulates the VSV to control the vacuum that is applied to the EGR valve, thus ensuring an optimal
EGR gas volume according to the engine condition and improving drivability.
Construction
1) VSV
The VSV controls the vacuum from the VCV that is applied to the EGR valve, in accordance with the duty signals received
from the ECM.
Page 532 of 4770
53ENGINEÐ1MZ±FE ENGINE
2) VCV (Vacuum Control Valve)
The VCV is a valve that regulates the intake manifold
vacuum that is appllied to the VSV to a constant level
(±17 kPa, ±130 mm Hg.)
The intake manifold vacuum that is supplied
through the S port is applied to the diaphragm. If this
force becomes greater than the spring force, the
diaphragm moves downward, allowing the valve to
close the S port and the atmosphere supplied
through the filter. Conversely, if the vacuum that is
applied to the diaphragm becomes weaker, the
diaphragm moves upward, causing the valve to
open and to shut off the atmosphere and supply the
intake manifold vacuum. This process is repeated to
regulate the vacuum in the Z port to a constant level.
3) EGR Valve Position Sensor
The EGR valve position sensor is mounted on the EGR valve. This sensor converts the EGR valve opening into a
voltage and sends it to the ECM as the EGR valve position signal.
Page 533 of 4770
54ENGINEÐ1MZ±FE ENGINE
Operation
The ECM executes duty control of the VSV to control the vacuum that has been regulated to a constant level by the
VCV, thus controlling the vacuum that is applied to the EGR valve.
Also, the EGR valve position sensor in the EGR valve detects the EGR valve opeining to provide feed back control
to the ECM, thus achieveing a target opining that is appropriate for the engine condition.
7. Others
A communication circuit has been provided between the ECM and the ABS & TRAC ECU in conjunction with the
adoption of the TRAC (Traction Control) system. The ECM sends signals such as the throttle position signal and the
engine speed signal to the ABS & TRAC ECU. In addition, the ECM executes fuel cutoff in accordance with the
request signals from the ABS & TRAC ECU.
Page 534 of 4770

55CHASSISÐCLUTCH
CHASSIS
CLUTCH
DESCRIPTION
As in the previous model, a dry type single plate clutch which is operated by hydraulic pressure is used on the new
model.
Along with the adoption of the 1MZ±FE engine model with manual transaxle, a release cylinder with a larger cylinder
diameter has been newly adopted to reduce the clutch pedal effort.
Specifications
Model
NewPrevious
Engine Type5S FE1MZ FE5S FEItem5S±FE1MZ±FE5S±FE
ClutchType
Dry Type Single Plate
Clutch
Diaphragm Spring
uu
OperationHydraulicuu
ClutchTypeDST*1uuClutch
CoverSize mm (in.)224 (8.82)236 (9.29)224 (8.82)
Clutch
Facing Size*2
mm (in.)
224 x 150 x 3.5
(8.82 x 5.91 x 0.14)236 x 150 x 3.5
(9.29 x 5.91 x 0.14)224 x 150 x 3.5
(8.82 x 5.91 x 0.14)
DiscFacing Area
cm
2 (in.2)217 (33.7)260 (40.4)217 (33.7)
MasterTypeConventionaluuMaster
CylinderCylinder Dia.
mm (in.)15.87 (0.62)uu
ReleaseTypeNon±AdjustableuuRelease
CylinderCylinder Dia.
mm (in.)20.64 (0.81)22.2 (0.87)20.64 (0.81)
*1: DST (Diaphragm Spring Turnover), *2: Outer Diameter x Inner Diameter x Thickness
Page 535 of 4770
56CHASSISÐMANUAL TRANSAXLE
MANUAL TRANSAXLE
DESCRIPTION
The 5S±FE engine model uses the same S51 manual transaxle as in the previous model.
The 1MZ±FE engine model ahs newly adopted the E153 manual transaxle. The basic construction and operation
of the E153 manual transaxle are the same as those of the '95 MR2. However, the differential gear ratio has been
changed to accommodate the characteristics of the engine.
Specifications
Model
NewPrevious'95 MR2
Transaxle TypeS51E153S51E153
Engine Type5S FE1MZ FE5S FE3S GTEItem5S±FE1MZ±FE5S±FE3S±GTE
1st3.5383.2303.5383.230
Gear2nd1.9601.9131.9601.913Gear
Ratio3rd1.2501.2581.2501.258
4th0.9450.9180.9450.918
5th0.731uuu
Reverse3.1533.5453.15347
Differential Gear Ratio3.9443.9333.9444.285
Oil Capacity
liters (US qts, Imp. qts)2.6 (2.7, 2.3)4.2 (4.4, 3.7)2.6 (2.7, 2.3)4.2 (4.4, 3.7)
Oil ViscositySAE75W±90uuu
Oil Grade API, GL±4 OR GL±5uAPI GL±3, GL±4 OR GL±5u
Page 536 of 4770
57 CHASSISÐAUTOMATIC TRANSAXLE
AUTOMATIC TRANSAXLE
DESCRIPTION
The A14OE automatic transaxle is used on the 5S±FE engine model, and the A541E automatic transaxle is used ont
he 1MZ±FE engine model. The basic construction and operation are the same as those of the previous model.
However, the pattern select switch has been discontinued both from the A140E and A541E automatic transaxles.
Specifications
Engine Type
5S±FE1MZ±FE
Transaxle TypeA140EA541EItemA140EA541E
G
1st2.810u
Gear
Ratio2nd1.549uRatio3rd1.000u Overdrive0.7060.735
Reverse2.296u
Counter Gear Ratio0.945u
Differential Gear Ratio3.9443.933
Fluid Capacity
liters
Transmission5.6 (5.9, 4.9)6.8 (7.2, 5.9)
liters
(US qts, Imp.qts)
Differential1.6 (1.7, 1.4)0.9 (0.9, 0.8)
Fluid TypeSAE75W±90u