K311 CVT (Continuously
Variable Transaxle)
Subtitle
K311 CVT (Continuously Variable Transaxle)
Overall
– A metal belt type continuously variable transaxle with electronic hydraulic control
Transaxle Type K311 K111 (Ref.)
2ZR-FAE 3ZR-FAE
Engine Type
(1.8 L) (2.0 L)
Pulley and Steel
Shift Mechanism Type ←
Belt
Single Pinion
Forward/Reverse Switching Double Pinion Type
Type Planetary
Mechanism Planetary Gear
Gear
Forward 2.386 to 0.411 2.396 to 0.428
Gear Ratio
Reverse*1 2.505 1.668
Differential Gear Ratio*2 5.698 5. 182
Shift Lever Position P–R–N–D–M ←
Fluid Type CVT Fluid TC ←
Fluid Capacity
8.6 (9.09, 7.57) ←
[Liter (US qts, Imp. qts)]
Weight (Reference) ??? ???
*1 : Planetary Gear Ratio Included
*2 : Reduction Gear Ratio Included
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K311 CVT
Components
Forward and Reverse Drive
Shift Mechanism Torque Conver
with Lock-up
Clutch
Primary
Pulley
Continuously
Variable Metal
Oil Pump
Transaxle and Belt
Metal Belt
Secondary
Pulley
Reduction
Parking Lock Gear
Mechanism
Differential
Gear
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K311 CVT
Components
Pattern
Select
3 Speed Switch
Sensors
Oil
Pressure
Sensor
CVT Fluid
Warmer
Valve Body Unit
Overflow (Hydraulic
Plug Control Unit)
Shift Position Indicator
(Combination Meter)
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K311 CVT
Major Difference Between K111 and K311
Type K311 K111
Double Pinion Type Single Pinion Type
Planetary Gear Unit
Planetary Gear Planetary Gear
5 Solenoid Valves 5 Solenoid Valves
•DS1 (Duty) •DS1 (Duty)
•DS2 (Duty) •DS2 (Duty)
Solenoid Valve
•DSU (Duty) •DSU (Duty)
•SLS (Linear) •SLS (Linear)
•SLT (Linear) •SL (ON/OFF)
Primary Pulley Single Piston Construction Double Piston Construction
Reduction Drive
Without Bearing With Bearings
Gear
Paddle Switch Without With
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K311 CVT
Identification Information
– The transaxle serial number is stamped on the case as shown in the illustration
Transaxle Serial
Number
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K311 CVT
Torque Converter with Lock-up Clutch
– Damper structure allowing lock-up from low speed range
Turbine Runner
Lock-up Clutch
Pump Impeller
Stator Damper Structure
One-way Clutch
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K311 CVT
Oil Pump
– The oil pump is combined with the torque converter, lubricates the parts and
supplies operating pressure to the hydraulic control
Oil Pump
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K311 CVT
Gear Train
– Consists of a planetary gear, continuously variable transaxle, reduction gear and
differential gear
Reverse Brake
Forward Clutch
Primary
Pulley
Input Shaft
Metal
Belt
Planetary Gear Unit
Secondary
Pulley
Reduction Gear
Continuously
Variable
Transaxle
Differential Ring Gear
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K311 CVT
Gear Train
– Operation (D Position)
D position D position
(Lowest Ratio) (Highest Ratio)
Pulley Width = OFF Pulley Width = OFF
Wide ON Narrow ON
Pulley Width Pulley Width
= Narrow = Wide
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K311 CVT
Gear Train
– Operation (N and R Position)
N position R position
Pulley Width OFF Pulley Width ON
= Wide OFF = Wide OFF
Pulley Width Pulley
= Narrow Width =
Narrow
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K311 CVT
Continuously Variable Transaxle and Metal Belt
– Performs speed ratio control by varying the pulley width with piston operation of
the primary and secondary pulleys
Metal Belt
Primary Pulley
Secondary Pulley
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K311 CVT
Continuously Variable Transaxle and Metal Belt
– The metal belt allows power transmission with the compressive effect of element
(element extrusion)
Metal Belt
Steel Ring
(Two Lines)
Element
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K311 CVT
Forward and Reverse Drive Shift Mechanism
– A double pinion type planetary gear is used
Forward Clutch
(With Centrifugal Fluid
Pressure Canceling
Mechanism)
Reverse
Brake
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K311 CVT
Forward and Reverse Drive Shift Mechanism
– Operation
[During Forward Driving] [During Reverse Driving]
Reverse Brake: Reverse Brake:
OFF ON
Forward Forward
Clutch: Clutch:
ON OFF
Input Inp
Shaft Sh
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K311 CVT
Valve Body Unit
– Consists of the upper and lower valve bodies, 5 solenoid valves and oil
temperature
Upper Valve
sensor Body
Bottom Side
Soleno
Valve S
Solenoid
Valve SLS
Oil Lower Valve Solenoid Valve DS
Temperature Body Solenoid
Sensor Solenoid Valve DS2
Valve DS1
Solenoid Valve Type Function
Controls the amount of fluid flowing into the
DS1
primary pulley (shift up control)
Duty
Controls the amount of fluid flowing from the
DS2
primary pulley (shift down control)
SLT Liner Controls the line pressure
DSU Duty Controls the lock-up clutch pressure
SLS Liner Controls the secondary pulley pressure
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Reference (K311 CVT)
Valve Body Unit
– Hydraulic control block diagram
Primary
Pulley
Oil
Pump
Secondary
Pulley
Valve
CVT Speed Belt Clamping Lock-up Manual
Body
Ratio Control Pressure Clutch Valve
Unit
Control Pressure
Control
Clutch /
Brake
Linear Linear Pressure
Solenoid Solenoid Solenoid Solenoid Solenoid Control
Valve DS1 Valve DS2 Valve SLS Valve DSU Valve SLT
ECM (CVT ECU)
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K311 CVT
Valve Body Unit
– Belt Clamping Pressure Control Mechanism
— Belt clamping pressure is controlled by regulating the secondary pulley
pressure
Line Pressure Primary
Line Pressure Modulator
Clutch Apply Pulley
Modulator Valve No.1
Valve No.3 Control Valve
Linear
Solenoid
Valve SLT
Linear
Secondary
Oil Primary Solenoid
Pulley
Pump Regulator Valve SLS
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K311 CVT
Valve Body Unit
– Speed Ratio Control Mechanism
— Speed ratio control is performed by controlling fluid flowing into and from the
primary pulley
Solenoid Speed Ratio Control Primary
Valve DS1 Valve No.1 Pulley
(Shift Up Control)
Bypass
Valve Speed Ratio
Control Valve No.2 Secondary
Oil Solenoid
(Shift Down Control) Pulley
Pump Valve DS2
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K311 CVT
Speed Sensor and Pressure Sensor
– 3 speed sensors and 1 pressure sensor are used
Speed Sensor NOUT NIN
(Hall IC Type) NT
Oil
Pressure
Sensor
Speed Sensor
NT NOUT Oil Pressure
(Hall IC Type) Speed Sensor NIN Sensor
(Pick-up Coil Type)
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K311 CVT
Parking Lock Mechanism
– The parking lock mechanism locks the rotation of the secondary pulley
Parking Lock Gear
Parking (Secondary Pulley)
Lock Pawl
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K311 CVT
CVT Fluid Warmer
– Function as fluid warmer after engine start
– Function as fluid cooler during driving
CVT Fluid : Engine Coolant Flow
Warmer : CVT Fluid Flow
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K311 CVT
CVT Fluid
– Use the Toyota Genuine CVT fluid TC
– Overflow type fluid level detection mechanism is used
Oil Pan
Refill
Front Plug
Overflow
Tube
Overflow Plug
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K311 CVT
Shift Lever
– Cable length adjustment mechanism
– Electrical type shift lock system
Temporary
Illustration Shift Lever
Shift Lock
Cable Length Release
Adjustment Button
Mechanism
Transmission
Control Cable
Shift Lock
ECU
Transaxle Shift Lock Soleno
•P Detection Switc
Assembly
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K311 CVT
System Diagram
Transaxle Assembly Accelerator Pedal Position Senso
Speed Sensor NT Throttle Valve Position Sensor
Engine
Speed Sensor NIN Control Crankshaft Position Sensor
Speed Sensor NOUT Engine Coolant Temp. Sensor
Park/Neutral Position CAN (V Bus No.1)
Switch DLC3
A/C A/C Swit
Oil Temp. Sensor
Amplifier
Oil Pressure Sensor CVT Yaw Rate and
Control Acceleration Sensor
Solenoid Valve DS1 ECM
Solenoid Valve DS2 Combination Meter
Shift Position Indicator
Solenoid Valve SLT
Vehicle Speed
Solenoid Valve DSU
Solenoid Valve SLS Shift Lever
Transmission Control Switch
Stop Light Switch
Pattern Select Switch (SPORT)
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K311 CVT
Electronic Control System
– These controls are basically the same as K111
Engine-CVT Integrated Control
Neutral Control
Acceleration Improvement Control
(Linear Feeling Improvement Control)
Shifting Control in Uphill/Downhill Traveling
Speed Ratio Control
7-speed Sport Sequential Shiftmatic
Lock-up Clutch Control
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K311 CVT
Fail-safe [1/2]
– This function minimizes the loss of operation when any abnormality occurs in
the
following parts
Malfunction Part Fail-safe Function CVT Operation
Calculate primary pulley speed (NIN) from
Speed Sensor NIN Normal
turbine speed (NT)
Speed Sensor Calculate secondary pulley speed (NOUT)
Normal
NOUT from wheel speed (vehicle speed sensor)
Calculate turbine speed (NT) from primary
Speed Sensor NT Normal
pulley speed (NIN)
Current to the solenoid valve DS1 is cut Speed ratio is lower
Solenoid Valve DS1
off than the normal
Speed ratio is
Current to the solenoid valve DS2 is cut
Solenoid Valve DS2 higher than the
off
normal
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K311 CVT
Fail-safe [2/2]
– This function minimizes the loss of operation when any abnormality occurs in
the
following parts
Malfunction Part Fail-safe Function CVT Operation
Current to the solenoid
Solenoid Valve DSU Lock-up clutch control is released
valve DSU is cut off
Current to the solenoid The line pressure becomes equal to
Solenoid Valve SLT
valve SLT is cut off the maximum oil pressure
• The belt clamping pressure is
Current to the solenoid maintained by the line pressure
Solenoid Valve SLS
valve SLS is cut off • Speed ratio is fixed to specified
ratio
Oil Temperature
Fix the temperature Normal
Sensor
Yaw rate &
Acceleration - Neutral control is canceled
Sensor
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Service Point (K311 CVT)
Replacement
– Transaxle assembly is an assembly replacement parts
(Do not disassembly the transaxle assembly)
Replaceable Parts
Park/Neutral
Position Switch
Oil Seal
Speed
Speed Sensor
Sensor (NOUT)
(NT)
Speed Oil
Sensor Pressure
(NIN) Sensor
Oil Seal
ATF Refill Plug
Warmer
Transaxle Assembly Overflow
(Assembly Replacement) Tube
Overflow Oil Pan
Plug
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Service Point (K311 CVT)
Initialization and Calibration
– After replacing the following parts, perform the initialization and calibration
Replacement
ECM Oil Pressure Sensor
Transaxle Assembly Yaw Rate and
Acceleration Sensor
Initialization Calibration
Yaw Rate and CVT Oil
CVT Calibrated
Acceleration Pressure
Value
Sensor Zero Point Calibration
Initialization
Calibration
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