Lexus RX300 (MCU15). Manual — part 46

EG

ENGINE — 1MZ-FE ENGINE

57

9. Engine Immobiliser System

The engine immobiliser system has been designed to prevent the vehicle from being stolen. This system
uses a engine ECU that stores the ID code of the authorized ignition key. If an attempt is made to start
the engine using an unauthorized key, the engine ECU prohibit fuel delivery and ignition, effectively disab-
ling the engine. For details see page 148 in the Engine Immobiliser System section.

10. Diagnosis System

The diagnosis system of the 1MZ-FE engine has adopted the EURO-OBD (Europe On-Board Diagnosis)
that complies with European regulations.
For details on the DTCs (Diagnostic Trouble Codes), refer to the LEXUS RX300 Repair Manual (Pub.
No. RM785E).

CHASSIS — U140F AUTOMATIC TRANSAXLE

CHASSIS

58

U140F AUTOMATIC TRANSAXLE

JDESCRIPTION

D The compact and high-capacity 4-speed U140F automatic transaxle [Super ECT (Electronically Con-

trolled Transaxle)] has been adopted to match the output characteristics of the new 1MZ-FE engine.
It is a compact, lightweight, and highly rigid automatic transaxle in which the transaxle, front and center
differentials, and the transfer unit have been integrated into a compact package.

D The snow mode switch is used. Further more, the European LHD models is provided with a kick down

switch.

D The MF2AV transfer unit that uses a viscous coupling has been adopted to accomplish the limited slip

effect of the center differential.

D Automatic transaxle fluid used is T-IV.

Transaxle
Section

Transfer
Section

Front and
Center
Differential
Section

185CH07

" Specifications A

Transaxle Type

U140F

Transfer Type

MF2AV

1st

3.938

2nd

2.194

Gear Ratio*

3rd

1.411

4th

1.019

Reverse

3.141

Differential Gear Ratio

3.291

Fluid Capacity

Liters (US qts, Imp. qts)

9.0 (9.5, 7.9)

Fluid Type

ATF Type T-IV

Transfer Gear Gain Ratio

0.341

Oil Grade

API GL-5

Transfer

Oil Viscosity

SAE 85W-90

Oil Capacity

Liters (US qts, Imp. qts)

0.9 (0.95, 0.79)

* : Counter Gear Ratio Included

CHASSIS — U140F AUTOMATIC TRANSAXLE

CH

BO

59

JPLANETARY GEAR UNIT

1. General

The U140F automatic transaxle has adopted a new gear layout. In the new gear layout, the counter drive
and driven gears are placed in front of the front planetary gear and the under drive (U/D) planetary gear
unit is placed above the counter shaft. Furthermore, the force transmission method has been changed by
eliminating the brake and the one-way clutch. As a result, a torque capacity that accommodates the high
output engine has been attained, while realizing a compact gear unit.

Input Shaft

Rear Planetary Gear

C

1

B

1

C

3

B

2

B

3

Counter Drive Gear

C

2

F

1

F

2

Front Planetary
Gear

185CH08

Under Drive (U/D)
Planetary Gear

Counter Driven Gear

Differential Drive Gear

" Specifications A

C

1

Forward Clutch

6

C

2

Direct Clutch

4

C

3

U/D Direct Clutch

The No of Discs

4

B

1

2nd Brake

The No. of Discs

4

B

2

1st & Reverse Brake

7

B

3

U/D Brake

4

F

1

No. 1 One-Way Clutch

The No of Sprags

28

F

2

U/D One-Way Clutch

The No. of Sprags

24

The No. of Sun Gear Teeth

43

Front Planetary Gear

The No. of Pinion Gear Teeth

17

y

The No. of Ring Gear Teeth

77

The No. of Sun Gear Teeth

31

Rear Planetary Gear

The No. of Pinion Gear Teeth

19

y

The No. of Ring Gear Teeth

69

The No. of Sun Gear Teeth

35

U/D Planetary Gear

The No. of Pinion Gear Teeth

28

y

The No. of Ring Gear Teeth

91

Counter Gear

The No. of Drive Gear Teeth

52

Counter Gear

The No. of Driven Gear Teeth

53

CHASSIS — U140F AUTOMATIC TRANSAXLE

60

2. Motive Power Transaxle

" Operating Conditions A

Shift

Lever

Position

Gear

Solenoid

Valve

SL1

Solenoid

Valve

SL2

Solenoid

Valve

S2

Solenoid

Valve

DSL

C

1

C

2

C

3

B

1

B

2

B

3

F

1

F

2

P

Park

ON

ON

OFF

OFF

f

R

Reverse

ON

OFF

OFF

OFF

f

f f

N

Neutral

ON

ON

OFF

OFF

f

1st

ON

ON

OFF

OFF

f

f f f

D

2nd

OFF

ON

OFF

OFF

f

f

f

f

D

3rd

OFF

OFF

OFF

OFF/ON*

f f

f

f

4th

OFF

OFF

ON

OFF/ON*

f f f

2

1st

ON

ON

OFF

OFF

f

f f f

2

2nd

OFF

ON

OFF

OFF

f

f

f

f

L

1st

ON

ON

OFF

ON

f

f f f f

*: Lock-up ON