›› Adjustment of the ATF pressure in the hydraulic system to
suit the various needs and requirements.
›› Control of cooling oil for clutch K1.
›› Pressure control for operation of the gear-shift actuators.
›› Oil supply for demand-based gear set lubrication for gear
train subsets 1 and 2.

Sub-Transmission 2 Valve 3
N439
Clutch valve K2
Sub-Transmission 2 Valve 4 N440
Gear train subset 2 safety valve 2

Sub-Transmission 1 Valve 3
N435
Clutch valve K1

Sub-Transmission 1 Valve 1
N433
Gear-shift actuator valve 1
for gears 5/1

Clutch Cooling Valve 1 N447
for clutch K1

Sub-Transmission 1 Valve 4 N436
Gear train subset 1 safety valve 1

Main Pressure Valve
N472

Sub-Transmission 2 Valve 2 N438
Gear-shift actuator valve 4
for gears R/4

Sub-Transmission 1 Valve 2
N434
Gear-shift actuator valve 3
for gears 3/7

Valve manifold for gear-shift actuator
valves and clutch cooling oil valve for
clutch K1
Sub-Transmission 2 Valve 1 N437
Gear-shift actuator valve 2 for gears
2/6
643_068

58

Hydraulic interfaces
ATF cooling – flow

ATF cooling – return

5th gear
1st gear
Reverse gear
4th gear
Clutch K1
Measurement
point for clutch
pressure K1

Clutch K2
Clutch
cooling, K2

Lubrication
Input shaft 1

Lubrication,
input shaft 2

Measurement
point for clutch
pressure, K2
Cooling channel
for control unit

Flow from ATF
pump

3rd gear

Return to ATF
pump
2nd gear

6th gear

7th gear
643_069

Intermediate plate

Printed gasket

The electro-hydraulic control module consists of 2 casing
sections as well as the valve manifold. Between the two
casing sections there is an intermediate plate. That intermediate plate acts, as a partition and together with the relevant
casing section forms corresponding oil channels for gearbox
control. Secondly, the intermediate plate acts as a seal
between the hydraulic interfaces and the transmission
housing.

The gasket for the interfaces between the hydraulic control module and the gearbox housing is printed on the intermediate
plate and cannot be replaced. When the Mechatronic module is detached, the gasket is damaged, which means that a proper
seal can no longer be obtained. Re-using such a Mechatronic module is not permissible. See page 59.

59

Description of solenoid valves
Sub-Transmission 2 Valve 4 N440
Gear train subset 2 safety valve 2
Valve N440 operates safety valve 2, which is responsible for the pressure
supply to clutch valve K2 N439 and to the gear-shift actuator valves N437/
N438. If a relevant malfunction occurs, N440 is used to hydraulically deactivate gear train subset 2.

Sub-Transmission 1 Valve 3 N435 – clutch valve K1
Sub-Transmission 2 Valve 3 N439 – clutch valve K2
These two solenoid valves are used to control the clutch pressure
for the clutch.

Mechatronic
module

Clutch Cooling Valve 1 N447 for clutch K1
This solenoid valve is used to control the cooling oil flow for clutch K1.
Sub-Transmission 1 Valve 1 N433
– Gear-shift actuator valve 1 for gear-shift actuator A for gears 5/1
Sub-Transmission 1 Valve 2 N434
– Gear-shift actuator valve 3 for gear-shift actuator C for gears 3/7

9
43

N

Sub-Transmission 2 Valve 1 N437
– Gear-shift actuator valve 2 for gear-shift actuator B for gears 2/6
Sub-Transmission 2 Valve 2 N438
– Gear-shift actuator valve 4 for gear-shift actuator D for gears R/4

N44

0

35

4

N

These solenoid valves control the 4 gear-shift actuators for selecting the
gears and the relevant neutral position.

33

4

N

4

43

N
7

44

N

N4

36

8

43

N

N4

72

7

43

N

643_097

Sub-Transmission 1 Valve 4 N436
Gear train subset 1 safety valve 1
Valve N436 operates safety valve 1, which is responsible for the pressure
supply to Sub-Transmission 1 Valve 3 N435 and to the gear-shift actuator
valves N433/N434. If a relevant malfunction occurs, N436 is used to hydraulically deactivate gear train subset 1.

60

Main Pressure Valve N472
The primary pressure valve adjusts the primary pressure (also called the system
pressure) in the hydraulic system according to the engine torque and the ATF
temperature.
N472 has a negative voltage/pressure characteristic. If the power supply is
lost, the maximum system pressure is applied. As a result, fuel consumption
may increase and gear-change noises may be more loudly audible.

Auxiliary hydraulic module1)

Clutch Cooling Valve 2 N448 for clutch K2
This solenoid valve is used to control the cooling oil flow for
clutch K2).
Basic information on the clutch cooling system for clutch K2 can
be found on page 26.

Parking Lock Solenoid Valve 2 N574
This solenoid valve is also called the parking lock disengagement
valve or PAV. It is used for disengaging the parking lock.
The operation of N574 is explained beginninag at page 40.

643_098

Parking lock module1)

Parking Lock Solenoid N486
N486 is an electromagnetic in function and acts as redundant
backup for holding the P-OFF function when the vehicle is moving
and when transmission setting N is selected.
The operation of N486 is explained on pages 37 and 40.

Parking Lock Solenoid Valve N573
This solenoid valve is also called the parking lock engagement valve
or PEV. As the name suggests, it is used for engaging the parking
lock.

643_099

The method of operation of N573 is explained beginning at page
38.

1)

he auxiliary hydraulic module and the parking lock module are controlled by Automatic Transmission Control Module 2 J1006.
T
See schematic diagram on page 72.
61

Auxiliary hydraulic module
The auxiliary hydraulic module is responsible for hydraulic
control of clutch cooling (K2), partial hydraulic control of the
parking lock, and serves as an interface for the Clutch Temperature Sensor 2 G659.
Electrical operation of the auxiliary hydraulic module is performed by Transmission Control Module 2 J1006. Refer to
page 72.
The auxiliary hydraulic module has the following functional
components:
›› The ATF pump.
›› Clutch Cooling Valve 2 N448 for clutch K2.
›› Parking Lock Solenoid Valve 2 N574 for disengaging the
parking lock.
›› A hydraulic self-holding valve (SHV) for controlling the
parking lock piston.
›› The contact and connection module.

Electrical connector T16b
Connection to Transmission Control
Module 2 J1006

Electrical connector for
Clutch Temperature Sensor 2 G659
643_075

ATF pump

Self-holding valve SHV

Parking Lock Solenoid Valve 2 N574
Parking lock disengagement valve PAV

Oil pipe connections to parking
lock module

Oil pipe connections to and from
Mechatronic module

Clutch Cooling Valve 2 N448
Clutch K2

Oil pipe
Connection to clutch cooling circuit
Clutch K2
643_076

62

Parking lock module
Electrical operation of the parking lock module is performed
by Transmission Control Module 2 J1006. Refer to page 72.

An Auto-P function automatically engages and disengages
the parking lock according to the operating status.

The parking lock is engaged by the force of the parking lock
spring – subject to the electro-hydraulic control system
adopting the appropriate switching status. The parking lock is
disengaged by hydraulic pressure.

The driver can engage the parking lock with the aid of the
Parking Lock Button E816 on the selector lever handle even if
the engine is running.

Electrical connector T16a
Connection to
Transmission Control Module 2
J1006

Parking Lock Sensor G747
See page 68

Parking lock spring
Parking lock piston
Parking Lock Solenoid
N486
A description of the function
can be found on page 41.

Bracket with sensor magnet for G747

Parking Lock
Solenoid Valve
N573
Parking lock engagement valve
PEV

Spring-loaded
tapered sliding
sleeve
643_077

63

Electronic module
The electronic module combines Gearbox Control Unit 1 J743
and the majority of the sensors in an integrated unit.

Gear Position Distance Sensor 1 G487
– for gear-shift actuator A – gears 5/1
Gear Position Distance Sensor 4 G490
– for gear-shift actuator D for gears R/4

Transmission Input Speed Sensor 2 G612
Speed sensor for input shaft 2

Transmission Input Speed Sensor 1 G632
Speed sensor for input shaft 1
Transmission Control Module J217

Transmission Fluid Temperature Sensor G93
Gear Position Distance Sensor 2 G488
– for gear-shift actuator B – gears 2/6
Gear Position Distance Sensor 3 G489
– for gear-shift actuator C – gears 3/7
643_070

Electrical connector
for Transmission Input Speed Sensor G182
and Clutch Temperature Sensor 1 G658

Electrical connector T16c for vehicle and transmission peripherals

Hydraulic Pressure Sensor 2 G546
Clutch pressure K2

Hydraulic Pressure Sensor 1 G545
Clutch pressure K1

Gearbox Control Unit 1 (also referenced as J743)

Electrical connector for printed circuit board

643_071
64

Transmission control modules
There are two modules for controlling the OBZ transmission.
›› Gearbox Control Unit 1 J743.
›› Transmission Control Module 2 J1006.
Dual-Clutch Transmission Mechatronic J743
Address Word 02
The designation J743 can refer to either the complete
Mechatronic module or only to the Gearbox Control Unit 1 in
the electronic module of the Mechatronic module. Gearbox
Control Unit 1 is the master control module for Transmission
Control Module 2 J1006.
The two modules along with Selector Lever Sensor System
Control Module J587 communicate via the Drivetrain CAN.
The schematic on page 72 provides an overall view of
which sensors and actuators are read/controlled by which
module.

Dual-Clutch
Transmission
Mechatronic
J743

Gearbox Control Unit 1
J743

643_072

Transmission Control Module 2 – J1006
Address Word C2
J1006 is known as a “smart actuator” control module and
controls the actuators assigned to it in response to commands from Gearbox Control Unit 1 J743. It also acts as an
intelligent interface for several sensors and input signals.
Refer to the chart on page 66.

Installation location for J1006

J1006 has the following functions:
›› Controlling the clutch cooling for clutch K2 (N448)
›› Controlling the electro-hydraulically operated parking lock
(N486, N573, N574).

Installation location in engine bay on lefthand side

›› Processing the signals from the parking lock sensor G747.
›› Processing the signals from Clutch Temperature Sensor 2
(clutch K2).
›› Processing the signals from the steering wheel tiptronic
controls.

643_003

65

Sensors and information
Speed sensors and speed data
Speed signals are among the most important items of information that a dual clutch transmission requires. The 0BZ
processes the following speed data:
››
››
››
››
››

Gearbox input speed.1)
Input speed for gear train subset 1.1)
Input speed for gear train subset 2.1)
Gearbox output speed.2)
Engine speed.2)

G612

Plug for engine
speed sensor socket

G632

Reluctor ring for input
shaft 1

Transmission Input Speed Sensor G182
G182 is used to detect the clutch input speed in real time.
The clutch housing, which is attached on one side to the dog
clutch and on the other to the inner plate carrier, acts as the
reluctor ring. See page 24, Figure 643_040.

Reluctor ring for input
shaft 2

The signal from G182 is used ...
›› For more precise control of the clutches.

Gearbox unit 1
Gearbox unit 2

›› For adapting the clutches.
›› For microslip control.
If G182 fails, the speed data from the Engine Speed Sensor
G28 is used as a substitute signal2).
Microslip control and certain adaptations cannot be carried
out.
The casing of G182 also houses Clutch Temperature Sensor 1
G658. See page 69.

his speed data is collected by the gearbox sensors and processed by Gearbox
T
Control Unit 1 J743.
2)
This speed data is provided by other control modules via CAN data communication and processed or calculated by Gearbox Control Unit 1 J743.
1)

Transmission Input Speed Sensor 1 G632
Speed sensor for input shaft 1
Transmission Input Speed Sensor 2 G612
Speed sensor for input shaft 2
These two speed sensors are used to register the clutch
output speeds (G632 = clutch K1 and G612 = clutch K2).
Together with the signal from G182, they allow the clutch
slip to be precisely calculated.
The signals from sensors G632 and G612 are used...
››
››
››
››

For microslip control.
For adapting the clutches.
For determining the synchromesh speed for gear shifts.
For calculating the gearbox output speed.

If one of the sensors fails, the affected gear train subset is
deactivated. Gearbox Control Unit 1 J743 then switches to an
appropriate safe mode.

66

Clutch Temperature Sensor 2 J659

Transmission Input Speed Sensor G182
Clutch Temperature Sensor 1 G658

Engine Speed Sensor
G28

Electrical connector for G659
on auxiliary hydraulic module

643_073

Transmission Input Speed Sensor G182
Clutch Temperature Sensor 1 G658

Clutch housing

Clutch Temperature Sensor 2 G659

Electrical connector for G659 on auxiliary hydraulic module

Transmission output speed – vehicle road speed –
direction of travel
Gearbox Control Unit 1 calculates the output speed and the
direction of travel on the basis of the speed signals from
G632/G612 and the currently selected gear. The output
speed provides the basis for calculating the vehicle road
speed.
To check the plausibility of the signals from the two sensors
G632/G612, the wheel speed data from the ESC control
module is referred to.
That information is required for the following functions:

643_074

›› For gear selection and determining the gear-shift points.
›› For detecting the direction of travel for plausibility-checking the gear selection (for example, when backing up, 1st
gear engagement is barred).
›› For the creep control function3).

Information
The sensors G182/G658 and G659 are identical in design. The speed sensor in G659 is not used.
67

Travel and position sensors
Gear Position Distance Sensor 1 G487
Gear Position Distance Sensor 2 G488
Gear Position Distance Sensor 3 G489
Gear Position Distance Sensor 4 G490