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GENERAL DESCRIPTION AND SYSTEM OPERATION

Transaxle Description

The new automatic transmission is an electronically controlled 4-speed automatic transmission with Lock-up mechanism.
The transmission is mainly composed of the torque converter with lock up clutch, newly developed 4-speed planetary gear unit, the hydraulic control system and the electric control system.

Electronical Components

Transmission Control Module (TCM)

The TCM primarily controls shift points and lockup engagement. It is located on the driver side under the instrument panel.
The transmission is controlled by an electronic shift system. The Transmission Control Module (TCM) processes input signals. From the information received, the TCM controls the transmission hydraulic system.
The electronic shift system consists of the following :

Transmission Range (TR) Switch

TR switch transmits the information which range includes shift lever of A/T to Starter and TCM.
TR switch transmits the information by combination of starter and reverse circuit to vehicle side directly without TCM.

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Shift Solenoid No 1,2 (SS1, SS2)

2 shift solenoids are installed directly in the valve body. The solenoids operate of ON and OFF by the control signal from TCM. Combinations of 2 solenoids, SS1 and SS2 changes gear ranges.

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Timing Solenoid

Timing solenoid is installed directly in the valve body. The solenoid operates of ON/OFF by the control signal from TCM. The solenoid change timing valve of inside the valve body, operate hydraulic control with apply and drain of forward clutch.

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Lock-Up Solenoid

Lock-up solenoid is installed in the valve body. It recieves control signal from TCM.
Lock-up solenoid operates the lock-up valve inside the valve body and controls the torque converter lockup function.

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Pressure Control Solenoid (PCS)

The pressure control solenoid (PCS) is located inside the valve body and regulates the transmission's fluid pressure system. It is internally grounded in the TCM and operates when it is supplied with battery voltage from the TCM, through the PCS and back to the TCM.
The battery voltage is controlled by a varying current from the TCM.
The strength of the current is a function of the throttle position.

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Transmission Fluid Temperature (TFT) Sensor

TFT sensor provides TCM with information on the transmission fluid temperature.
The TCM uses information from the TFT sensor to calculate the gear shift points and to engage the torque converter lockup function.

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Input Shaft Speed (ISS) Sensor

ISS sensor is located on the upper position of the transaxle and detects A/T input speed from the rotation number of the direct clutch drum.
They transmit to TCM as a signal.

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Output Shaft Speed (ISS) Sensor

OSS sensor is located on the upper position of the transaxle and detects the vehicle speed from the rotation number of the differential gear.

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Shift Control

When the ATF is below specification (15°C), 4th up-shift is prevented.

Hydraulic Control System

Based on the hydraulic pressure created by the oil pump, TCM sends signals to solenoid and hydraulic control system governs the hydraulic pressure acting on the torque converter, planetary gear, clutches and brakes in accordance with the vehicle driving conditions.

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Automatic Transaxle System

Function of Components


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Component
Function
C1
Forward Clutch
Connects input shaft and front sun gear.
C2
Direct Clutch
Connects input shaft and planetary carrier.
C3
Reverse Clutch
Connects input shaft and rear sun gear.
B1
O/D & 2nd Brake
Prevents rear planetary sun gear from turning either clockwise or counterclockwise.
B2
2nd Brake
Prevents outer race of F1 from turning either clockwise or counterclockwise, thus preventing the rear sun gear turning conterclockwise.
B3
1st & Reverse Brake
Prevents planetary carrier from turning either clockwise or counterclockwise.
F1
No.1 One-way Clutch
When B2 is operating, this clutch prevents rear sun gear from counterclockwise.
F2
No.2 One-way Clutch
Prevents planetary carrier from turning counterclockwise.
Planetary Gear
These gears change the route through which driving froce is transmitted, in accordance with the operation of each clutch and brake, in order to increase or reduce the input and output speed.

Operations of Clutches and Brakes


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Clutch & Brake
Operation
C1
Forward Clutch
Connects intermediate shaft and front sun gear.
C2
Direct Clutch
Connects input shaft and Planetary carrier.
C3
Reverse Clutch
Connects intermediate shaft and rear sun gear.
B1
O/D & 2nd Brake
Lock rear sun gear
B2
2nd Brake
Lock rear sun gear
B3
1st & Reverse Brake
Lock Planetary carrier
F1
1way Clutch No.1
Lock counterclockwise rotation of rear sun gear, when B2 operations
F2
1way Clutch No.2
Lock counterclockwise rotation of planetary carrier
Position
Solenoid
Clutch
Brake
One-way Clutch
Shift 1
Shift 2
Timing
C1
C2
C3
B1
B2
B3
F1
F2
P ON ON OFF OFF OFF OFF OFF OFF OFF OFF OFF
R V<9Km/h ON ON OFF OFF OFF ON OFF OFF ON OFF OFF
V≥9Km/h ON ON ON OFF OFF OFF OFF OFF OFF OFF OFF
N
ON
ON
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
D
1st
ON
ON
OFF
ON
OFF
OFF
OFF
OFF
OFF
OFF
ON
2nd
ON
OFF
OFF
ON
OFF
OFF
OFF
ON
OFF
ON
OFF
3rd
OFF
OFF
OFF
ON
ON
OFF
OFF
ON
OFF
OFF
OFF
(3↔4)
OFF
ON
ON↔ OFF
ON↔ OFF
ON
OFF
OFF↔ON
ON
OFF
OFF
OFF
4th
OFF
ON
OFF
OFF
ON
OFF
ON
ON
OFF
OFF
OFF
2
1st
ON
ON
OFF
ON
OFF
OFF
OFF
OFF
OFF
OFF
ON
2nd
ON
OFF
OFF
ON
OFF
OFF
ON
ON
OFF
ON
OFF
3rd
OFF
OFF
OFF
ON
ON
OFF
OFF
ON
OFF
OFF
OFF
1
1st
ON
ON
OFF
ON
OFF
OFF
OFF
OFF
ON
OFF
ON
2nd
ON
OFF
OFF
ON
OFF
OFF
ON
ON
OFF
ON
OFF

D-1st Gear

Position
Solenoid
Clutch
Brake
1 way Clutch
Shift 1
Shift 2
Timing
C1
C2
C3
B1
B2
B3
F1
F2
D 1st ON ON OFF ON OFF OFF OFF OFF OFF OFF ON
1 1st ON ON OFF ON OFF OFF OFF OFF ON OFF ON

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"D" - 1st Gear

  1. Input shaft rotates clockwise.
  2. Front sun gear rotates clockwise.
  3. Planetary short pinion rotates itself counterclockwise.
  4. Planetary long Pinion rotates itself clockwise.
  5. Planetary carrier is going to rotate counterclockwise.
  6. Ring gear rotates clockwise.
  7. Counter drive gear rotates clockwise for ring gear and one.
  8. Counter drive gear rotates counterclockwise
  9. Differential gear drive pinion rotates counterclockwise for counter driven gear and one.
  10. Differential gear rotates clockwise.
( Engine Brake)
  1. Counter drive gear and Planetary ring gear rotates counterclockwise.
  2. Planetary long pinion rotates itself counterclockwise.
  3. Planetary short pinion rotates itself clockwise.
  4. Planetary carrier revolves clockwise due to rotation itself counterclockwise of planetary long pinion, but driving force loses due to free of 1 way clutch NO.2 (F2). Therefore Engine brake does not operate.

D-2nd Gear

Position
Solenoid
Clutch
Brake
1 way Clutch
Shift 1
Shift 2
Timing
C1
C2
C3
B1
B2
B3
F1
F2
D 2nd ON OFF OFF ON OFF OFF OFF ON OFF ON OFF
2 2nd ON OFF OFF ON OFF OFF ON ON OFF ON OFF

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"D" - 2nd Gear

  1. Input shaft rotates clockwise.
  2. Front sun gear rotates clockwise.
  3. Planetary short pinion rotates itself counterclockwise.
  4. Planetary long Pinion rotates itself clockwise.
  5. Rear planetary sun gear is going to rotate counterclockwise.
  6. Planetary carrier revolves clockwise due to reaction force of planetary long pinion.
  7. Ring gear rotates clockwise.
  8. Counter drive gear rotates clockwise for ring gear and one.
  9. Counter driven gear rotates counterclockwise
  10. Differential gear drive pinion rotates counterclockwise for counter driven gear and one.
  11. Differential gear rotates clockwise.
( Engine Brake)
  1. Counter drive gear and planetary ring gear rotates counterclockwise.
  2. Planetary long pinion rotates itself counterclockwise.
  3. Planetary short pinion rotates itself clockwise.
  4. Rear sun gear rotates clockwise due to rotation itself counterclockwise of planetary long pinion, but driving force loses due to free of 1 way clutch No.1(F1). Therefore Engine Brake does not operate.

D-3rd Gear

Position
Solenoid
Clutch
Brake
1 way Clutch
Shift 1
Shift 2
Timing
C1
C2
C3
B1
B2
B3
F1
F2
D 3rd OFF OFF OFF ON ON OFF OFF ON OFF OFF OFF

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"D" - 3rd Gear

  1. Input shaft rotates clockwise.
  2. Planetary short pinion and planetary long pinion can not rotate itself, and planetary gear unit rotates clockwise as one.
  3. Counter drive gear rotates clockwise for ring gear and one.
  4. Counter drive gear rotates counterclockwise
  5. Differential drive pinion rotates counterclockwise for counter driven gear and one.
  6. Differential rotates clockwise.
( Engine Brake)
Driving force is connected to input shaft directory without 1 way clutch.
Therefore Engine Brake operates.

D-4th Gear

Position
Solenoid
Clutch
Brake
1 way Clutch
Shift 1
Shift 2
Timing
C1
C2
C3
B1
B2
B3
F1
F2
D 4th OFF ON OFF OFF ON OFF ON ON OFF OFF OFF

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"D" - 4th Gear

  1. Input shaft rotates clockwise.
  2. Planetary carrier revolves clockwise.
  3. Planetary long pinion rotates itself clockwise.
  4. Rear planetary sun gear is going to rotate counterclockwise.
  5. Planetary long pinion revolves clockwise while rotating itself clockwise.
  6. Ring gear rotates clockwise.
  7. Counter drive gear rotates clockwise for ring gear and one.
  8. Counter driven gear rotates counterclockwise.
  9. Differential gear drive pinion rotates counterclockwise for counter driven gear and one.
  10. Differential gear rotates clockwise.
( Engine Brake)
Driving force is connected to input shaft directory without 1 way clutch.
Therefore Engine Brake operates.

Reverse Gear

Position
Solenoid
Clutch
Brake
1 way Clutch
Shift 1
Shift 2
Timing
C1
C2
C3
B1
B2
B3
F1
F2
R V<9km/h ON ON ON OFF OFF ON OFF OFF ON OFF OFF
V≥9km/h ON ON ON OFF OFF OFF OFF OFF OFF OFF OFF

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Reverse Gear

  1. Input shaft rotates clockwise.
  2. Planetary long pinion rotates itself counterclockwise.
  3. 1st & reverse brake(3) operates. (Lock rotates planetary carrier)
  4. Ring gear rotates counterclockwise.
  5. Counter drive gear rotates counterclockwise for ring gear and one.
  6. Counter driven gear rotates clockwise.
  7. Differential gear drive pinion rotates clockwise for counter driven gear and one.
  8. Differential gear rotates counterclockwise.
( Engine Brake)
Driving force is connected to input shaft directory without 1 way clutch.
Therefore Engine Brake operates.


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