Module 1 AT (Automatic Transmission)

Explanation of the system mechanism taking into account the

transmission design.
List of locations, mechanisms and functions of components.
Training Explanation of the power flow to each gear taking into account the
Goals solenoid valve operation chart.
Take the necessary actions after changing the part and list the
preventive measures necessary for maintenance.

1. General description
1.1 Introduction
1.2 Model range
1.3 Specifications
2. Design
2.1 Main features
2.2 Input and output elements
3. Components
3.1 mechanical components
3.2 Hydraulic control components
3.3 TCU Input Components
3.4 TCU Output Components
4. Power train
4.1 Clutch and brake operation
4.2 Power flow
5. Maintenance
5.1 Oil level adjustment
5.2 TCM Learning
5.3 Inhibitor switch cable adjustment
1. General description
1.1 Introduction
A transmission is a device that changes and transfers engine power (speed and turning power) to the wheels
depending on the driving state of the vehicle. Transmissions can be manual or automatic. A transmission is installed
between the clutch and the drive shaft or between the clutch and the final gear.
The functions of a transmission are the following:
• Greater driving force when starting or driving uphill.
• Lower motor rotation speed thanks to increased rotation power.
• No load on the engine during starting.
• Put the vehicle in reverse, because the engine cannot perform reverse rotation.
• High speed rotation of wheels during high speed driving.
An automatic transmission operates the automatic clutch and transmission control, which normally must be done
with a manual transmission. The automatic transmission consists of a torque converter that functions as a clutch, a wet
multi-plate clutch, which controls the planetary gears, and a brake band. Since the engine and the power transfer
device are connected by a fluid medium, it absorbs vibrations and shocks and shifts into the appropriate gear for
engine performance at all times. Compared to the manual transmission, the automatic transmission consumes approx.
10% more fuel, but many drivers prefer the automatic transmission for its driving comfort.

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1.2 Model range

In order to meet the specific needs of different vehicles and markets, Hyundai uses different automatic transmissions in
its product range, e.g. ex.:
• Model: A163
Model A163 is an electronically controlled front-wheel drive 3-speed automatic transmission manufactured by AISIN,
Japan. There are two varieties: A163-A for 0.8E engines (DOM only) A163-B for 1.0£ engines, Application: MX (Atos,
Visto, Atos Prime)
• Model: A4AF3
It is the latest development among alpha automatic transmissions (advanced alpha automatic transmission). It is an
electronically controlled front wheel drive 4-speed transmission produced by HMC. Application: X -3, LC (Accent), TB
(Getz), LD,C-car Vehicles are equipped with an alpha engine)
• Model: F4A series and F5A series
Model F4A51 is an automatically controlled front-wheel drive 4-speed automatic transmission manufactured by HIVEC
and installed on the vehicle which has the engine volume of 2.0L or more. The F5A51 model is an electronically
controlled front-wheel drive 5-speed automatic transmission manufactured by HMC and is based on the 4-speed version.
Depending on the actual vehicle there are several versions available, such as the A5HF1 for NF Sonata. Various versions
are also available for 4-speed transmissions.
W4A51 is a kind of HIVEC F4A51 4-speed automatic transmission with a 4-wheel drive mechanism. Application: Santa
Fe
• Model: AW30-40LE
The AW30-40LE model is an electronically controlled rear-wheel drive 4-speed automatic transmission produced by
AISIN, Japan. Application: HP (Terracan)
• Model: FRA
It is an electronically controlled front-wheel drive 4-speed automatic transmission produced by JATCO, Japan.
Application: MX (Atos, Visto, Atos Prime)

• Model: KM175
It is a Kyoto model of electronically controlled front-wheel drive 4-speed automatic transmission manufactured by
HMC and there are two varieties: KM175-5 is for 2.0SOHC KM175-6 is for 2.0DOHC engine. Application: Y-
3(Sonata), Santamo

• Model: F21-450
It is an electronically controlled front-wheel drive 6-speed automatic transmission produced by AISIN, Japan. The

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 TCM is placed on top of the transmission housing and all sensors are positioned inside the automatic transmission
assembly. :
In Veracruz)

• Model: A5SR1/2
It is an electronically controlled front-wheel drive 5-speed automatic transmission from JATOCO (Japan) and
produced in Korea by Hyundai Power-Tech. Application: H-1 (TQ) CRDi 2.5L, BK (Genesis Coupe) 2.0L

• Model: A4CF1/2
It is an electronically controlled front wheel drive 4/5 speed transmission developed by HMC. Application: HD
(Elantra) 1.6L/2.0L, FD (i30) 1.6L/2.0L

• Model: B400/B600
It is an electronically controlled front wheel drive 6-speed automatic transmission from AISIN, Japan. Application:
BH (Genesis) 3.3L/3.8L

• Model: 6HP26
It is an electronically controlled rear-wheel drive 6-speed automatic transmission from ZF, Germany. The TCM and
inlet sensors are integrated into the valve body. Application: BH (Genesis) 4.6L, BK (Genesis Coupe) 3.8L

• Model: A6LFx, A6MFx

It is an electronically controlled front-wheel drive 6-speed automatic transmission developed by Hyundai Motor
Company. Speed sensors are integrated into the valve body.
Application: LM (Tucson, ix35), YF (Sonata)

• Model: 6HP19
It's an electronically controlled rear-drive 6-speed automatic transmission from ZF. The TCM and inlet sensors are
integrated into the valve body. Application: BK (Genesis coupe) 3.8L

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1.3 Specifications

Categories A6GF1 A6MF1

Applicable engines V-1.8MPI, Y-1.6MPI Lambda- 3.3, 3/8

Max torque allowed (kg.m) 18kgf-m 33.5/45kgf-m

Length (mm) 373 387

Weight (kg) 73 94

1 4,400 4,651

2 2,726 2,833

3 1,834 1,842

Speed ratio 4 1,392 1,387

5 1,000 1,000
6 0,774 0,722
°
R 3,440 3,390

Clutch 2 set (OD, 35R) 2 set (OD, 35R)

Component Brake 3 set (UD, LR, 26) 3 set (UD, LR, 26)

O.W.C. 1 set 1 set

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 2. Design
2.1 Main features

REAR planetary support oil pump assembly

CENT planetary support converter housing
torque converter
L/R Brake DEL planetary support
O.W.C.
Clutch O/D

Brake 2/6
35R brake
U/D brake

primary shaft
Manual transmission
bearing cover
Box secondary shaft
Differential
transmission gear
Conj. diff.
T/F transmission
T/F Actuator
parking gear

An automatic transmission is made up of a torque converter (which transfers power from the engine), a gear device
(which converts the energy transferred from the torque converter), a hydraulic system (which changes the gear ratio
by changing the settings of the gear device) and an electronic control system (which controls the overall function of
an automatic transmission).
An automatic transmission receives signals from various sensors and switches and controls the solenoid valve, clutch
and brakes for conversion of the power received from the torque converter into appropriate output of the planetary
gear for different gear shifts.

Electronic section hydraulic section Mechanical section

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2.2 Input and output elements

Power and grounding

Input and output speed

sensors

temperature sensor oil

temperature

Inhibitor switch

switch
sport mode

NDE ABS/ESC
Speed
Engine RPM
vehicle
TPS/APS
Air flow
of admission
The TCM processes the signals received from the sensors to perform optimal gear changes, smoother shifting, and
improve fuel efficiency. The input section receives various signals from the sensors, the control section determines
the optimal gear selection based on the sensor signals and controls the hydraulic pressure and the converter clutch,
and the output section executes the controls based on the TCM orders. The TCM works as follows.
• Determines optimal gear selection using sensor data.
• Changes gears if the current gear is not optimal (prevents shifting).
• Determines the activation of the converter clutch - it activates and deactivates.
• Regulates line pressure based on current torque level.
• Perform automatic transmission diagnosis.

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 3. Components converter
clutch
3.1 mechanical components
• ) Torque converter

1. Functions and roles

The torque converter, which transfers power from the engine to the
transmission, is made up of an impeller, a turbine and the stator. Its
functions are the following.

• Power Transfer: Transfers power from the engine to the transmission

Stator
• Torque boost: Torque is increased by a stator to overcome the torque
on the motor shaft
• Oil pump: Rotate the oil pump actuator gear to pump oil
• Improved fuel efficiency: Engine speed (power) is transferred to the transmission via the converter
clutch
2. Mechanism

• Torque multiplication
Due to the application of the stator, motor torque can be multiplied.
Torque multiplication is possible because the stator redirects the reflux
current to reach the impeller blades that have the same direction as the
impeller. It works as follows: during start-up, the impeller rotates at
engine speed and the turbine is stopped. The fluid driven by the impeller
reaches the turbine and transfers energy (engine torque) to it.

3 Stator
• Hydraulic clutch operation O Impeller
Upon leaving the turbine again, the fluid flow is redirected by the (2 Turbine
stator, so that the fluid stream acquires the same direction towards which
the impeller (motor) is rotating. This creates a force that attempts to reverse the direction of rotation of the
stator so that it is opposite to that of the impeller (motor). Due to the one-way clutch, this movement is
restricted. Therefore the oil flow is redirected to the direction of rotation of the engine. This sudden change of
direction causes a blockage of fluid return. The force created by this acts as additional force on the turbine (in
the direction of rotation), so that the output torque is increased. Another positive effect is that the fluid that
returns to the impeller does so in the direction of rotation and almost free of vortices.

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1. Functions and roles

Because a hydraulic coupling requires a minimum speed Turbine stator

difference between the impeller and turbine (slip) resulting in
higher fuel consumption, modern torque converters additionally
incorporate a lockup clutch or converter clutch. The lockup clutch
prevents any slippage in the torque converter during cruising by
locking the turbine against the impeller (front cover) to make
them rotate together.

Impeller
Converter Clutch

2. Mechanism

< Converter clutch applied > <Converter clutch released>

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2) converter clutch
• Converter clutch applied
Hydraulic pressure enters between the inner surface of the torque converter hub and the reaction shaft together
with the plate (damping piston) and the front cover to connect it to the turbine.

• Converter clutch released

Hydraulic pressure passes through the input shaft and presses the clutch plate in the opposite direction,
separating the clutch plate from the front cover.

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3) planetary gear
• Functions and roles
A simple planetary gear set consists of the following elements: ring gear (ring gear), pinions (planetary gears), the
planetary carrier, and the sun gear.
toothed crown

Pinion
Front view of planetary gear

Hydraulic control is necessary to maintain or connect the specific parts of the planetary gear assembly, allowing the
transmission of power. In order for a planetary gear set to transmit torque, one element must be driven (input) and
another must remain stationary for the third to be driven (output). Depending on which part is kept fixed or connected,
the gear ratio is changed.

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4) Brake and clutch

< Multi-disc brakes, clutch (plate and disc) > < One way clutch >

1. Functions and roles

As the name already indicates, clutches and brakes are used to connect or hold mechanical parts.
• Brakes
It allows gear changes by preventing the fixation or rotation of various pieces of the planetary gear.
• Clutch
Transfers engine power to the planetary gear input elements during gear changes.
• One way clutch
does not require hydraulic pressure. Its mechanism allows rotation in a
only direction. If the L/R brakes are used without a one-way clutch, shifting from first to second gear requires
releasing the L/R brakes and applying the secondary brakes. A change hit occurs if the release and application are not
done at the correct time. By using the one-way clutch instead of the L/R brakes, shifting from first to second gear does
not require the use of both sets of brakes; It is possible to use only the secondary brakes to smooth the change to a
higher gear.

35R clutch

< Clutch/brake position >

2. Mechanism
• Clutch and brake
Multiple discs consist of a retainer that holds the clutch discs and plates. The clutch plates are connected to the
retainer. The clutch discs, on the contrary, are not.
If the clutch is activated, pressure is supplied behind the piston. The piston will then move and press the clutch discs
and plates together. The retainer and hub are connected in this case.

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If the pressure is released, the return spring will push back on the piston causing the clutch plates and discs to
separate again. Retainer and hub are disconnected.
In the case of brakes, as the basic construction is the same, the operating principle is also the same. The difference is
that clutches connect two rotating parts and the brake connects one piece to the transmission housing, keeping it
stationary.
The operation of the clutch and brakes in different gears according to fluctuations in hydraulic pressure is explained
in chapter 4. Power train.

<not applied> <applied>

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 3.3 Hydraulic control components
1) Oil pump
< Oil flow
• Functions and roles
It is driven by the torque converter and supplies
pressurized fluid to the torque converter, the hydraulic
control system including the clutches and brakes, and
provides the necessary amount of fluid for lubrication and
activation of the clutch and brakes.

2) valve body
• Functions and roles
The main feature of the valve body in the front-wheel drive
6-speed automatic transmission of the small sedan is the application of linear solenoid valve to improve the stability and
control of the hydraulic system. Additionally, the PCV pressure regulation screw is used to minimize pressure differences,
resulting in better shift quality. Several new technologies are also applied including dual reducing valves and converter
clutch release control. A filter is added to each solenoid valve to improve durability and cleanliness.

T/CON(VFS,N/L)
35R(VFS,N/H)
26(VFS,N/L) 35R PCV
26 PCV UD(VFS,N/H)
OD(VFS,N/H)
SS-B (ON/OFF)
SS-A (ON/OFF)

line pressure
(VFS,N/H)

Check valve

REDUCING valve
UD PCV

OD PCV

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 3) Main valve
• reducing valve
A valve that uses line pressure to keep hydraulic pressure lower than first.

• Check valve
The regulating valve adjusts the hydraulic pressure generated by the oil pump to the line pressure. The hydraulic pressure
valve resists spring force, causing the line pressure to adjust to
proper hydraulic pressure for different gear changes.
A VFS (Variable Force Solenoid) is installed to adapt optimal
line pressure control to different driving conditions and improve
fuel efficiency.
• PCV (Pressure Control Valve) and solenoid valve
A pressure control valve prevents a sudden drop in hydraulic
pressure when hydraulic pressure is released from the clutch to
suppress an increase in input shaft revolutions. The solenoid valve controls the PCV to adapt to different gear changes
and indirectly controls the clutch and brakes.
A command from the TCU increases/decreases currents in the solenoid valve allowing hydraulic pressure to be
supplied through the pressure control valve. The supplied hydraulic pressure is transferred to the clutch or brakes
through the spring inside the PCV, allowing gear changes. The mechanism and operation of the solenoid valve are
explained in more detail in the following section.

• Manual valve
A manual valve engages the driver's seat gear shift lever and directs flow with each gear shift to supply line pressure to the
valves.

<Manual valve>

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4) Accumulator
• Functions and roles
An accumulator is installed in the hydraulic fluid channel of the clutch and brakes. Temporarily built-up hydraulic pressure
is supplied to the clutch during gear shifting and prevents sudden application of the clutch/brake to allow smooth gear
changes. The accumulator also absorbs the pulsation created when the solenoid valve is operated and prevents a sudden
drop in hydraulic pressure when a solenoid valve is stopped.

Body of the

internal valve

To the clutch or brake Piston and spring

ND accumulator

Piston and spring

accumulator (5EA)

Piston
transmission case
manual

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3.3 TCU input components
1) Input and output speed sensor
1. Functions and roles
An input/output speed sensor allows the TCM to produce optimal driving performance by detecting the automatic
transmission input revolutions and axle rotation speed and sending the data to the TCM to determine the gear shift
time.
Conventional HIVEC automatic transmission is an external type with an independent input shaft speed sensor and a
secondary shaft speed sensor. However, a modern automatic transmission has an integrated transmission-mounted
input/output speed sensor. The primary shaft speed sensor detects the rotational speed of the turbine inside the torque
converter and the secondary shaft speed sensor detects the rotational speed of the transfer drive gear.
Output speed sensor

Input speed sensor

• Gear shift control

The TPS value received from the secondary shaft
speed sensor and the engine is used as a signal to
control gear changes.

• Converter clutch control

The TCU uses input/secondary shaft speed and
revolutions to control the converter clutch.
0 1000 2000 3000 4000 5000 6000 7000
Secondary shaft speed sensor revolutions

• Operating margin adjustment Converter Clutch: Speed Sensor From

secondary, TPS, oil temperature the axis
• Formula to calculate converter clutch slip: Engine revolutions -
input shaft speed sensor = converter clutch slip (May
consult current data)
2. Mechanism diode
A hall IC that detects the movement of the tone wheel is located inside the
sensor. The turbine rotation speed and transfer drive gear rotation speed
detected with the hall effect are converted into electrical signals and sent to
the TCU. The TCU maps the received data and uses it for optimal solenoid
valve control and gear shifting timing.

Hall IC

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2) Inhibitor switch

• Functions and roles

The inhibitor switch detects the gear shift position (PRND) of the shift lever and sends the operating data to the TCM.
The inhibitor switch is installed on the gearbox and is connected with the manual control shaft.
When the gear lever is not in the "P" or "N" position, the electrical circuit for starting the engine is in the OFF state.
Therefore, the engine does not start in this state even if the ignition switch is in the "START" position.

<Gear lever operation>

• Sports mode

Manual mode is used to establish a gear shift pattern that meets the driver's needs. Upshift/downshift signals are
analyzed to control gear changes.
• Mechanism
When the driver moves the shift lever, the wires connect to the shaft that protrudes from the transmission and causes
the connector on the rotor to rotate and contact the shift lever generating 4 terminal signals (S1, S2, S3, S4). P, R, N
and D produce the signals shown in the following table.

Category Q R N d

S1 1 0 0 0

S2 0 1 0 0

S3 0 0 1 0

S4 0 0 0 1
PCM Inhibitor Switch Signals

<Switch internal circuit>

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3) OTS (Oil Temperature Sensor)
1. Functions and roles
The oil temperature sensor is installed directly on the valve body, as shown in the image. The sensor converts the oil
temperature inside the automatic transmission into an electrical signal and transmits it to the TCM.
Oil temperature is a critical element of automatic transmission control. The oil temperature sensor sends data to the
TCM, which is then used for important purposes, including converter clutch operation/failure detection, variable oil
temperature control, and hydraulic control during gear changes.

<Oil temperature sensor>

2. Mechanism
The oil temperature sensor uses an NTC thermistor that changes its resistance level according to changes in oil
temperature. The TCM turns on the sensors and changes the sensor output according to ATF temperature changes.

Temperature (°C)

-20°C —4.12V
60°C — 1.06V

Inversely relationship
proportional

Resistance (Q), voltage (v)

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3.4 TCU output components
1. Solenoid valve
2. Functions and roles
The solenoid valve is installed in the valve body of the automatic transmission and acts as an actuator that operates
according to electrical signals received from the TCM. Following signals from the TMC, the PCV (Pressure Control
Valve) is controlled to adapt to different gear changes, resulting in indirect control of the hydraulic pressure of the
clutch or brakes inside the automatic transmission. .

N.H solenoid valve Solenoid valve N.H

. pressure control 35R (VFS) .
line (VFS)

N.L Solenoid valve

control of the
. shift A (On-Off)

N.L Solenoid valve

control of the solenoid valve
.
change B (On- torque converter
Off) (VFS)
Solenoid valve /
OD (VFS) N.L
Solenoid valve
Solenoid valve .
N.H UD (VFS)
26 (VFS)
. N.H N.L
. .

For conventional HIVEC automatic transmissions, a separate solenoid valve has been installed for each clutch or
brake. However, the solenoid valve in the front-wheel drive 6-speed
automatic transmission uses more than two shift levers at the same time,
such as the 35R clutch or the 26 brake.
X • VFS (Variable Force Solenoid): Variable line pressure solenoid
• N/H (normally high): Provides 0-50mA hydraulic pressure when the
solenoid valve is not controlled
• N/L (normally low): Supplies 850mA hydraulic pressure when the
solenoid valve is controlled.
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Control
 • SS-A (Shift Control Solenoid Valve A): Directs the operating pressure of OD/C and LR/B to LR/B when LR/B is
operating.
• SS-B (Shift Control Solenoid Valve B): Guides the flow direction to the target gear when 35R/C is operating.
3. Mechanism
The solenoid valve induces magnetic force created according to control signals from the TCM to move the plunger
held inside the product by springs and hydraulic pressure, opening ports and creating control pressure. Amperage is
canceled when the solenoid valve is not controlled. As a result, the coil moves to the left through the spring force, as
shown in the figure below, and the oil pressure is transferred to effect control. When the solenoid valve is controlled,
amperage is applied. The plunger moves to the right through magnetic force along with the coil. The valve closes the
supply side, forcing pressure through the exhaust and reducing line pressure.

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4. Solenoid valve control
• Normal High Type VFS Solenoid Valves
UD, OD, 35R and line pressure control solenoid valve are normal high type. When the solenoid valve is
energized, the corresponding clutch or brake is disengaged. In the current data of the scanner, it shows 50 mA
when power off and 850 mA when power on respectively. However, due to the different capacity, the line
pressure solenoid valve is different from the others (even those which are the same normal high type) and
therefore the line pressure solenoid is not interchangeable with the others.
• Low Normal Type VFS Solenoid Valves
The torque converter clutch and brake solenoid valve 26 are normal low type. When the solenoid valve is
energized, the corresponding clutch or brake is engaged. In the current data of the scanner, it shows 50 mA when
power off and 850 mA when power on respectively.
• Normal Low Type On/Off Solenoid Valves
Shift solenoid A and B are normal low type. The A shift solenoid functions to control the LB brake pressure along
with the OD VFS solenoid. The B shift solenoid functions to control the 35R clutch in conjunction with the 35R
VFS solenoid. It is displayed on or off on the scanner depending on the current status.
4. Solenoid valve operation
Element Solenoid valve operation
1 T/
UD/B OD/C 35R/C 26/B LR/B O.W.C SS-B SS-A LP 35R/C 26/B OD/C UD/B
CON
.
P/N ei Off On 0 0 852 0 0 0

R ei ei On Off 0 0 0 0 852 852

1 E △ ei Off Off 0 0 852 0 852 0

2 IT e ei th Off Off 0 0 852 852 852 0

3 e ei On Off 0 0 0 0 852 0
D/S
4 e ei Off Off 0 0 852 0 0 0

5 ei ei On Off 0 0 0 0 0 852

6 th th ei
ei Off Off 852 0 852 852 0 852

th Solenoidth valve operation table

Because the name of the clutch and brake has been coined by the gear position engaged by the clutch and brake
correspondingly, for example, brake 26, clutch 35R; we can assume in what gear these elements are geared.
That is, the brake 26 works in 2nd and 6th gear and the clutch 35R works in 3rd , 5th and reverse gear. Only the LR
brake engages in park and neutral when power is not transferred to the output gear. Therefore, the hydraulic pressure is
lower than the gear range. Also the operating elements in 1st gear differ depending on the range (D or sport mode) as
follows.
1a - D: As soon as the output shaft speed is above 100 rpm (vehicle speed is 8kph), the LR brake is disengaged and the
OWC will operate. In contrast, if the speed is less than 6kph, the LR brake is engaged again.
The crawl brake is engaged while the gear ratio is less than 1:1. This is the reason why it is named 'ultra-slow' in the
advance range. The overdrive clutch engages from 4th to 6th gear, in the high speed range.

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4. Power train

• A: Hydraulic pressure is applied but no power is transmitted.

Clutch and brake operation table

4.2 Power flow

1) Gear, clutch and brakes

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 2) 1st gear

3) 2* gear

Power transmission route :

1. Turbine —» Primary shaft —> Rear sun gear —» Rear annulus gear
Front ring gear
UD/B Front sun gear fixing -• Exit
2. Rear planetary carrier —> Center planetary
carrier — —> Center ring gear — Output
Fixing the central sun gear 26/B

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4) 3rd gear

Power transmission route

1.Turbine —» Primary shaft —> Rear sun gear —» Rear annulus gear
Front ring gear UD/B Exit
Front sun gear fixing

2.Primary shaft 35R/C Central sun gear — Center planetary support — Sun gear

the central circular ring — Front planetary support —» Output

5) 4* gear

Power transmission route :

Turbine —» Primary shaft —» OD/C Rear Planetary Carrier Rotation
I —» Rear sun gear
—> Rear ring gear —> Front ring gear —•
UD/B Front sun gear fixing Exit

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6) 5th gear

Power transmission route

OD/C Rear planetary carrier rotation

Turbine — Primary shaft — —» Rear planetary support

> 35R/C Central sun gear rotation
—> Center planetary carrier — —> Center ring
gear — Front planetary carrier —> Output

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6) 5th gear

7) 6th gear

OD/C Rear planetary support

Turbine – Primary shaft Rear planetary carrier rotation

crown gear
Center planetary support Central sun gear rotation

central circular — Front planetary support — Outlet

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8) 5th gear

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5. Maintenance
5.1 Oil level adjustment
1) ATF (Automatic Transmission Fluid) Overview
It transmits power within the torque converter and functions as the hydraulic fluid for hydraulic devices (valves,
clutch, brakes). It also lubricates and cools rotating parts.
A shortage of ATF causes an influx that creates abnormal pressure in the oil pressure circuit, resulting in delayed gear
changes, abrasion of the clutch/brake discs or deterioration of the ATF. On the contrary, an excess of ATF causes the
gear to rotate and cause bubbles; which ultimately has the same consequence as a shortage of ATF.
2) ATF inspection
• Color
ATF contains a red dye to distinguish it from other transmission oils and motor oil. The transparent red color at the
beginning gradually turns brownish as the mileage increases. Finally, it turns light brown.
• Type and volume
ATF SP-IV(A6LF1/2/3: Approx. 7.8 liters, A6MF1/2: Approx. 7.1 liters)
• Replacement intervals
Change the ATF if it turns dark brown or black, if there is a burning smell, or if ground metal is present on the oil
level gauge when checking the oil level. Change the ATF after traveling more than 100,000 km.

3) Procedure
1. Open the ATF filler cap and add 700cc.
2. Start the engine (after starting the engine and while the ATF
temperature rises, do not operate in the stall state).
3. With the engine idling, use a scanner to check that the automatic
transmission oil temperature sensor reads 55°C in the P position.
4. With the engine running, step on the brake and move the gear lever
from P -> R -> N -> D -> N -> R - P twice and then engage the P
position (stay more than 2 seconds in each position).
5. Raise the vehicle with a lift and remove the oil level plug located at the
bottom of the automatic transmission valve body cover.
6. If a small amount of oil leaks, the oil level is normal. If the filtered oil is
more than 900cc (50~60°C) for 2 minutes, this means the oil level is too high.
7. Check the small leak mentioned above and then replace the oil level plug (check the tightening torque).
8. If there is no oil leakage, it means that the oil is insufficient. Start from step 1.
9. If you are replacing all ATFs, remove the magnetic plug, drain the oil, replace the plug, add 5 liters of oil, and
then follow steps 1 to 7.
10. If the oil drains completely, pour 5ty then perform the above procedure.
5.2 TCM Learning
1) Purpose
TCM learning minimizes the influence of mass production drift for smoother gear shifts, greater shift consistency, and
prevention of durability loss due to increased mileage. It can be understood as a "break in" an automatic transmission.
Carry out TCM training in the following cases.
• When replacing the transmission.
• When replacing the TCM (do an automatic A/T reset on the GDS at the same time).
• When updating the TCM.

2) Procedure
Category Change Conditions Repetition Common conditions
3~4 times Temp. of oil = 40~90°C
There should be no APS
UD/B N.D. Engine speed < 700 RPM. change during gear changes
Remains in N for more than 2 (3%).
sec.
26/B 1-2 APS = 10~30% (15~20%
recommended)
35R/C 2-3

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 OD/C 3-4
• Learning for UD brake
When the shift lever is moved from the N to D position, the crawl brake is engaged. Many technicians may forget to
do this training, even if the procedure is simple. Hold position N for more than 2 seconds and then move to position
D. Then return to position N after at least 2 seconds. It must be repeated 3 or 4 times to complete the process. By
doing this learning, the TCM will learn the basic control factor for the UD brake and will be used and compensated
when engaging the UD brake is required in other shifting activities.
• Brake training 26
As you may already know, brake 26 is engaged for the first time when the gear changes to a higher gear, from 1st to
2nd gear. When shifting is performed under normal driving conditions, the basic hydraulic control factor for the
brake 26 is memorized so that it is transferred and used for the other shifting control.
• Learning for the 35R clutch
As you may know, the 35R clutch engages for the first time when the gear shifts into a higher gear, from 2nd to 3rd
gear. When shifting is performed under normal driving conditions, the basic hydraulic control factor for the 35R
clutch is memorized so that it is transferred and used for the other shifting control.
• Learning for OD clutch
As you may already know, the OD clutch engages for the first time when the gear shifts into a higher gear, from 3rd
to 4th gear. When shifting is performed under normal driving conditions, the basic hydraulic control factor for the
OD clutch is memorized so that it is transferred and used for the other shifting control.
When learning more than 4 elements, it is transferred to the rest of the shift control each time those elements are
engaged or disengaged, that is why a maximum gear shift (6th gear) is not necessary for TCM learning.

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5.3 Inhibitor switch cable adjustment
1) Purpose
If an inhibitor switch DTC is generated or an intermittent failure occurs during starting with gear in P or N, it may be
due to a defective cable rather than a defective component. Inspect the shift cable bracket and correct adjustment.
2) Procedure
1. Position the shift lever in the "N" position. the way shift cable
2. Loosen the control lever coupling nut so that the control cable and lever are
free. switch body
3. Position the manual control lever in the neutral position.
4. Loosen the inhibitor switch mounting bolts and rotate the inhibitor switch
body so that the hole in the end of the manual control lever aligns with the
hole (cross section AA in the figure) in the inhibitor switch body flange.
shift position.
5. Tighten the shift position switch body mounting bolts to the specified
torque. At this time be careful that the position of the switch body does not
change.
6. Gently pull the transmission control cable in the direction of the front side of Section AA
the vehicle in order to remove excess slack, and then tighten the adjusting
nut.
7. Double check that the shift lever is in the "N" position.
8. Check that each range on the drive side operates and functions correctly for each shift lever position.

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