2021-2026 Audi RS E Tron Gt 4 Door Power transmission User Manual
MyCarUserManual.com
USER MANUALS FOR EVERY MAKE & MODEL

Power transmission for Your Audi RS E Tron Gt 4 Door First Generation (2021-2026)

Power transmission  
Overview  
684_170  
34  
The Audi e-tron GT (type F8) is equipped with two three-phase current drives. They are regulated by motor control unit J623, which  
controls the drive torque via the power electronics.  
In addition, the motor control unit is responsible for controlling the two-speed transmission 0ME.  
Maximum torques at the axles  
The two-speed transmission 0ME on the rear axle of the Audi e-tron GT increases both the driving dynamics and the efficiency of  
the vehicle.  
The diagram gives a qualitative overview of the drive torques at the axles as a function of the speed, taking into consideration the  
gear set on the rear transmission unit.  
684_336  
35  
Selector mechanism  
684_172  
The driver’s desired transmission position (R, N or D) is transmitted via the selector mechanism to motor control unit J623.  
The data are transmitted to data bus diagnostic interface J533 via the infotainment CAN bus and from there to motor control unit  
J623 via FlexRay.  
Transmission position D is the only position available for driving forwards. The gear selection can be influenced using the Audi drive  
select modes efficiency, comfort and dynamic.  
The parking lock function is activated in conjunction with the electromechanical parking brake. This happens when button E538 is  
pressed to activate the parking brake when the vehicle is stationary, and this status is communicated to the motor control unit. It is  
also possible for the parking lock function to be activated via the Auto-P function as part of the exit concept.  
Shift schematic  
684_166  
36  
From the basic position – X – there are two forward positions (A1, A2) and two rearward positions (B1, B2). The selector lever re-  
turns to the basic position – X – after every operation.  
Key:  
Basic selector lever position & current transmission position  
Selectable positions which change the transmission position  
Selectable positions which do not change the transmission position  
Software lock – deactivation by pressing the brake pedal  
Shift behaviour  
When the vehicle is driven in transmission position D, 2nd gear is normally used for driving off. If transmission position R is selec-  
ted and then position D, 1st gear remains selected. At driving speeds above approx. 20 km/h, the vehicle shifts into 2nd gear.  
Manoeuvring, rocking the vehicle backwards and forwards to free it  
The software lock is activated in transmission position N after approx. one second. This allows rapid changing of the transmission  
position from D to R and vice versa without applying the brake. This makes it easier to change transmission positions when ma-  
noeuvring. It also makes it possible to free the vehicle if necessary by rocking it forwards and backwards.  
Note  
A tone will sound briefly when R is selected.  
Activating the parking lock function (P-ON)  
The button for electromechanical parking brake E538 is marked with a white illuminated symbol.  
If button E538 is pressed at vehicle speeds < approx. 2 km/h, the parking brake is actuated via ABS control unit J104. The parking  
brake brings the vehicle to a standstill by blocking the wheels on the rear axle.  
The red symbol for the parking brake appears in the instrument cluster.  
Directly after the rear wheels are blocked by the parking brake, the parking lock function is activated by blocking two-speed trans-  
mission unit 0ME on the rear axle. There is no physical parking lock. By engaging two gears simultaneously, the transmission unit  
blocks itself, which acts as a parking lock. Parking lock indicator lamp K320 lights up on the selector lever control.  
Auto-P function (P-ON/OFF)  
The parking lock function is activated automatically if the drive system is switched off when transmission position D or R is selected  
and the vehicle is stationary.  
If the vehicle’s drive system is activated, the parking lock function is deactivated when the driver presses the brake pedal and se-  
lects transmission position D, R or N.  
Exit concept (P-ON)  
The parking lock function is automatically activated if the driver’s door is opened and the driver’s seat belt is unbuckled when the  
vehicle is stationary with transmission position D or R selected.  
Transmission position N  
The parking lock function remains deactivated (P-OFF): Car wash function  
The parking lock function remains deactivated if the ignition is switched off when transmission position N is selected. A 30-minute  
countdown starts, during which time the parking lock function remains deactivated. After approx. 30 minutes, the parking lock  
function is activated automatically. The countdown is interrupted if the ignition is switched on or the vehicle begins to move.  
37  
Function diagram – selector mechanism  
684_169  
Key:  
E313  
Selector lever with:  
E538  
E888  
G727  
J587  
Y5  
Electromechanical parking brake button  
Button for automated driving  
Selector lever position sender  
Selector lever sensors control unit  
Selector lever position display with K320 parking lock indicator lamp  
J104  
J519  
J533  
J623  
J1121  
ABS control unit  
Onboard supply control unit  
Data bus diagnostic interface  
Motor control unit  
Driver assist systems control unit  
Earth wire  
Positive wire  
LIN bus  
FlexRay  
FlexRay Low  
Convenience CAN, high  
38  
Convenience CAN, low  
CAN bus High (Infotainment)  
CAN bus Low (Infotainment)  
Single-speed transmission – 0MG  
Single-speed transmission – 0MG has the factory designation EQ450-1K. It comprises two planetary gear stages on a common  
shaft. They are referred to as the input stage and the output stage.  
The planetary gear stages reduce the speed of the electric motor with a reduction ratio of i = 8.053 for forwards driving and revers-  
ing.  
The torque, which is increased according to the ratio, is transmitted to the wheels via a planetary gear differential.  
The transmission unit is flanged onto the electric drive motor; together with the intermediate housing of the electric drive motor,  
this forms an area with a separate oil supply. As the gears are submerged in the oil pan, they churn the oil upwards. This lubricates  
and cools the components. The gear oil is cooled via the cooling system for the electric drive motor. The heat is exchanged via the  
intermediate housing of the electric drive motor.  
684_173  
39  
684_064  
Key:  
Planetary gear set - output stage  
Planetary gear set - input stage  
40  
Transmission schematic  
684_177  
The electric drive motor transmits the torque via the sun gear into the input stage. The torque is transmitted to the planet carrier  
of the output stage via the annulus of the input stage. The planetary gears of the output stage transmit torque to the stationary  
annulus and the sun gear of the output stage, which in turn transmit torque to the planet carrier of the input stage. The torque is  
transmitted from the planet carrier of the output stage to the planet carrier of the planetary gear differential, and via its differen-  
tial gears and sun gear to the axles and the wheels.  
41  
Planetary gear differential  
684_174  
42  
684_186  
The torque is transmitted via the planet carrier of the output stage to the differential gears (planetary gears of the differential).  
The planet carrier of the output stage also serves as the planet carrier of the planetary gear differential. The differential gears  
transmit the torque further to the axles via the sun gears.  
Reference  
For further information on the planetary gear differential, please refer to SSP 675 “Audi e-tron (type GE)” (refer to arti-  
cle “Lightweight planetary gear differential”).  
43  
Two-speed transmission 0ME  
684_339  
The Audi e-tron GT (type F8) is fitted with two-speed transmission unit 0ME on the rear axle as standard equipment. The transmis-  
sion unit is fitted parallel to the axle and has two continuous speed reduction stages and one planetary gear set. The transmission  
unit has the factory designation EQ550-2P.  
An active differential lock is available as optional equipment for the Audi e-tron GT. This active differential lock is standard equip-  
ment on the Audi RS e-tron GT.  
44  
Reference  
You can view the components of two-speed transmission unit – 0ME in detail using the AR application AR "Audi e-tron  
GT (Type F8) - Drive / Power Transmission".  
Three selector elements - a freewheel, a dog clutch and a multi-plate clutch- enable the transmission unit to perform the following  
tasks:  
›
›
Shifting between 1st and 2nd gear. The different ratios are achieved using a planetary gear set.  
Reversing in transmission position R. This is done by reversing the direction of rotation on the electric drive motor in 1st gear  
and engaging the dog clutch for power transmission.  
›
›
Activating the parking lock function. This is done by blocking the gears and locking them in position.  
Enabling neutral position.  
The shift matrix shows the interaction between the selector elements required for the transmission functions.  
Transmission position/gear  
Ratio  
1 (R/N)  
2
15,560  
8,160  
Transmission position D is the only position available for driving forwards. The gear selection can be influenced using the Audi drive  
select modes efficiency, comfort and dynamic.  
Exploded view  
684_370  
The multi-plate clutch and dog clutch are operated via the selector fork and the release fork, which are controlled by the shift  
drum.  
The shift drum is actuated by gear actuator VX65 via a spur gear drive.  
45  
684_369  
The two fixed-ratio gear sets 1 and 2 are always involved in the power transmission and yield a constant ratio of 8.16 : 1. This ratio  
corresponds to that of 2nd gear, as here the planetary gear set is blocked, and therefore rotates without speed transformation (i.e.  
1 : 1).  
For 1st gear and reverse gear, the planetary gear ratio of 1.907 is applied. Together, the two gear ratios (8.16 x 1.907) yield a ratio  
of 15.56 : 1.  
There is no physical neutral position in the transmission unit. This means that the electric drive motor is always engaged for power  
transmission to the wheels.  
46  
Freewheel  
684_367  
The freewheel is one of the three selector elements of two-speed transmission 0ME. It provides the basis for 1st gear, for shifting  
from 2nd gear back to 1st gear, and for the parking lock function. Its task as a component is to block the sun gear from turning in  
one direction, and to ensure free rotation in the other direction (i.e. of freewheel rotation).  
The rotor of the freewheel interlocks with a shaft journal connecting it to the sun gear. The stator of the freewheel has a flange  
with dog teeth that allow it to be mounted for co-rotation in the transmission unit housing.  
On the end of the rotor of the freewheel are teeth for the dog clutch. When the dog clutch is engaged, these teeth interlock with  
the teeth on the stator of the dog clutch and block the sun gear in the direction of freewheel rotation.  
This means that the sun gear is blocked in both directions when the dog clutch is engaged.  
The shift matrix shows the interactions between the selector elements that are required for the transmission functions.  
Note  
The term “freewheel” has two meanings:  
›
›
A component that blocks the rotation of a shaft in one direction (locking direction) and allows the shaft to turn free-  
ly in the other direction.  
A state in which kinetic energy allows the vehicle to roll along freely. This is also referred to as coasting.  
47  
Dog clutch  
684_368  
The dog clutch is one of the three selector elements of two-speed transmission 0ME. It is required for reverse gear, recuperation in  
1st gear, and the parking lock function.  
When the dog clutch is engaged, it blocks the rotor in the direction of freewheel rotation.  
As the rotor interlocks with a shaft journal connecting it to the sun gear, the sun gear is blocked in both directions of rotation when  
the dog clutch is engaged:  
›
›
In one direction of rotation by the freewheel  
In the other direction of rotation by the dog clutch  
The stator of the dog clutch is mounted for co-rotation in the transmission housing via the dog teeth on the stator. It is engaged  
and disengaged by a selector fork that moves it along a shaft in the transmission unit housing. When engaging the clutch, the se-  
lector fork slides the stator towards the rotor, and the dog teeth on the side of the stator mesh with the dog teeth on the rotor.  
The shift matrix shows the interactions between the selector elements that are required for the transmission functions.  
48  
Actuation of the dog clutch  
684_270  
When the shift drum rotates, the guide pin engaged in the guide slot causes the selector fork to extend.  
This causes the stator to be moved back and forth via the two spring-loaded joints connecting it to the selector fork.  
When the dog clutch engages, the stator is moved towards the rotor. The spring-loaded joint ensures that the selector fork does  
not block when the dog teeth are aligned tooth on tooth. If this happens, it causes the dog teeth to be pre-loaded and to engage,  
and the dog clutch engages as soon as the rotor turns.  
Motor control unit J623 detects the “tooth on tooth” position via clutch jaw position sensor G1016. In order to engage the dog  
clutch, the electric drive motor is actuated minimally, if necessary, so that the rotor turns far enough for the dog teeth to engage,  
and sensor G1016 detects a fully engaged dog clutch.  
49  
Dog clutch, disengaged  
684_366  
Key:  
Dog clutch engaging/engaged  
Dog clutch disengaging/disengaged  
50  
Points to note regarding how the dog clutch is operated  
Dog clutch aligned tooth on tooth  
Dog clutch engaged  
684_363  
684_364  
The freewheel exhibits a certain degree of elasticity when subjected to torque in the direction of rotation in which it blocks. The  
greater the torque the freewheel is subjected to, the more it rotates slightly in the direction in which it blocks. This causes the rotor  
of the dog clutch to rotate as well.  
This effect is exhibited in situations such as:  
›
›
Powerful acceleration in 1st gear  
Parking on an incline when the parking lock function is activated and the parking brake is not engaged  
If this happens, the dog clutch may engage when there is minimal overlap in the “tooth on tooth” position due to the rotation of  
the freewheel under high torque. In this situation, there is a risk that the freewheel springs back when the torque eases off, caus-  
ing the dog clutch to be pre-tensioned in such a way that it cannot be disengaged again.  
If the dog clutch cannot be released, it is not possible to shift up from 1st into 2nd gear.  
To prevent the situation described here, the dog clutch is prevented from engaging when shifting from 2nd gear back into 1st gear  
at high loads. In this case, the shift drum remains in shift state C (dog clutch still disengaged), (refer to image “684_337”). As  
recuperation in 1st gear requires the dog clutch to be engaged, recuperation is not possible at this stage.  
The dog clutch is not engaged until the operating conditions are no longer critical.  
51  
Multi-plate clutch  
684_269  
Two-speed transmission 0ME is equipped with a multi-plate clutch that is closed by a diaphragm spring when the clutch is not op-  
erated.  
When the multi-plate clutch is closed, it connects the planet carrier with the annulus. As a result, the planetary gear set is blocked  
and co-rotates as a unit. No speed reduction takes place in the planetary gear set.  
This shift state is required for 2nd gear and for the parking lock function.  
52  
Disengaging/engaging the clutch  
684_289  
The shift drum actuators are responsible for disengaging/engaging the multi-plate clutch.  
An angled guide on the shift drum actuates the release fork for the multi-plate clutch via a roller with needle bearings. The release  
fork actuates the release bearing to disengage and engage the multi-plate clutch.  
When the multi-plate clutch is disengaged, the planetary gear set is no longer blocked.  
The planetary gear set therefore serves as a speed reduction stage for 1st gear and reverse gear.  
The multi-plate clutch is open when transmission position N is activated. This makes it possible to push the vehicle even if the dog  
clutch and freewheel are engaged.  
The movement of the release fork is registered by clutch position sender G476.  
53  
Shift drum actuation  
684_371  
The dog clutch and the multi-plate clutch are actuated via the shift drum.  
For this purpose, the shift drum has a guide groove for the selector fork of the dog clutch, and an angled guide for the release fork  
of the multi-plate clutch.  
Gear actuator VX65 actuates the shift drum via a two-stage reduction gearing. This enables the gear actuator motor to apply the  
amount of force required for actuation.  
Motor control unit J623 determines the appropriate gear based on the current operating status and activates gear actuator VX65  
via a sub-bus system (motor control unit CAN bus).  
Shift drum locking mechanism  
When the vehicle is moving, it must not be possible for the parking lock function to be activated. There is a locking gate on the face  
of the toothed wheel for the shift drum for this purpose, (refer to image “684_372”). When the vehicle is driven, the locking pin of  
parking lock solenoid N486 protrudes into the locking gate and prevents the shift drum from turning to shift state A (P-ON).  
If the vehicle comes to a halt, current flows to solenoid N486, which causes the locking pin to be pulled out of the slot. Now the  
shift drum can turn to shift state A (P-ON); the parking lock is then engaged.  
Voltage is induced in the coil when the locking pin is pulled out of the slot. This voltage signal is evaluated as feedback and provides  
assurance that the locking pin has been removed from the locking gate.  
When the sensors of the selector fork and release fork detect shift state A (P-ON), solenoid N486 can be switched off. Spring force  
causes the locking pin to extend; it lies against the end face of the gear wheel, removed from action.  
Gear actuator VX65  
It communicates with motor control unit J623 as a slave control unit via a sub-bus system (motor control unit CAN bus). As the  
gear actuator is involved in the immobiliser system, it is secured with anti-theft bolts. A special bit insert VAS 6970 is required to  
fit and tighten these bolts.  
If the gear actuator or the transmission unit is renewed, the function “Work steps after component replacement” must be carried  
out using the vehicle diagnostic tester via address word 0001 “Engine electronics, functions”.  
54  
684_372  
684_365  
Shift drum positions and the resulting shift states  
684_337  
The motor control unit determines the desired gear/the desired shift state and delivers this information to gear actuator VX65. In  
doing so, it is influenced by the current Audi drive select mode, load requirement and speed (see shift programme).  
Depending on the desired shift state, gear actuator VX65 turns the shift drum via the spur gear drive. The angle that the shift drum  
turns results in shift state A, B, C or D for the dog clutch/the multi-plate clutch.  
When switching from state A to state D, the shift drum control logic requires going through states B and C.  
Shift state A  
The multi-plate clutch and the dog clutch are engaged. In conjunction with the locking effect of the freewheel, the entire transmis-  
sion unit is blocked. Shift state A is applied for the parking lock function (see shift matrix).  
In the case of a defective selector mechanism, the parking lock function can be disengaged using the diagnostic tester and the  
function 0001 Activation - release of parking lock. For this to be possible, the shift drum actuators must be intact, motor control  
unit J623 must be able to actuate gear actuator VX65, and the vehicle electrics must have sufficient power. There is no provision  
for mechanically releasing the parking lock function.  
Shift state B  
The multi-plate clutch is disengaged and the dog clutch is engaged. This shift state is applied in 1st gear, when recuperating in 1st  
gear, for reversing or for transmission position N (see shift matrix). Transmission position N is used to deactivate the parking lock  
function (P-OFF); it also makes it possible to push the vehicle and provides the car wash function.  
Shift state C  
55  
This shift state constitutes the preparation for shifting into 2nd gear. If the multi-plate clutch is already disengaged, the first step  
is to disengage the dog clutch. This allows the sun gear of the planetary gear set to start rotating in the direction of the freewheel  
(it will overtake the freewheel) as the clutch closes.  
State C is also shifted through when shifting from 2nd gear back into 1st gear. When the multi-plate clutch disengages, the plane-  
tary gear is no longer blocked. The planetary gears start to move and transmit power to the sun gear to provide the speed reduction  
for 1st gear. For this to happen, the sun gear must be held in locking direction by the freewheel; it is stationary.  
Transition from shift state C to B  
Before the dog clutch engages, it must be ensured that 1st gear is able to transmit power. This likewise ensures that the sun gear,  
and therefore the rotor of the dog clutch, is not moving and that it is already possible to engage the non-synchronised dog clutch  
during driving.  
The dog clutch is engaged in order to recuperate in 1st gear and to enable driving in reverse gear.  
Shift state D  
The multi-plate clutch engaged and the dog clutch is disengaged. This shift state is applied in 2nd gear (see shift matrix).  
Shift program  
Audi drive se-  
lect mode  
Drive torque distribution  
Driving off for-  
wards  
During driving  
2nd gear  
Shifting to speed reduction for 1st gear  
[4]  
efficiency  
comfort  
dynamic  
Front axle prioritised  
For reverse gear and in the case of spe-  
cial shifting behaviour  
2nd gear  
[4]  
Economical four-wheel drive  
prioritised  
2nd gear  
Yes, below approx. 50 km/h with high  
load requirement and for reverse gear  
2nd gear  
Performance-oriented four-  
wheel drive  
1st gear  
2nd gear from ap- Yes  
prox. 70 -  
110 km/h  
The motor control unit selects the desired gear according to the Audi drive select mode, load requirement and vehicle speed.  
The shift drum actuators apply the selected gear.  
Audi drive select mode “efficiency”  
The transmission unit remains exclusively in 2nd gear to provide maximum range. Only in transmission position R is the shift state  
for 1st gear applied to provide reverse gear.  
Reverse gear is then applied by reversing the direction of rotation of the electric motor.  
Audi drive select mode "comfort"  
In comfort mode, the vehicle drives prioritises 2nd gear for driving off, and remains in 2nd gear. The vehicle only switches to 1st  
gear to provide maximum performance at speeds below approx. 50 km/h with a very high load requirement from the driver.  
Audi drive select mode "dynamic"  
In dynamic mode, the vehicle drives off in 1st gear. Depending on the load requirement, the vehicle shifts into 2nd gear starting  
from speeds between approx. 70 km/h and 110 km/h. As a rule, the vehicle shifts back into 1st gear if the driving speed falls below  
this range. The exact speed at which the downshift occurs depends on how the vehicle is being driven.  
Special shifting behaviour  
When the vehicle is driven in transmission position D, 2nd gear is normally used for driving off. If position R is selected and then  
position D, 1st gear remains selected initially. Only after reaching a driving speed above approx. 20 km/h does the vehicle shift into  
2nd gear.  
[4] Driving off in 1st gear is also possible; see “special shifting behaviour”  
56  
Transmission schematic  
684_179  
The gearbox schematic shows the gearbox when the vehicle is stationary and in transmission position N.  
57  
Shift matrix  
Trans-  
mission  
posi-  
Dog clutch  
Multi-plate  
clutch  
Free-  
wheel  
Remarks  
tion/  
gear  
Drive  
R
Engaged  
Disengaged  
Reverse gear is applied by reversing the direction of rotation of the  
electric motors. The planetary gear set of two-speed transmission  
0ME acts as a speed reduction stage in the same way as for 1st  
gear. The torque is transferred via the sun gear which is blocked by  
the dog clutch.  
(pre-loaded) (actuated)  
N
P
Engaged  
Disengaged  
The transmission unit does not have a neutral position, i.e. there is  
no shift position in which the power flow between the electric drive  
motor and the wheels is interrupted. Transmission position N cor-  
responds to the shift position for 1st gear and reverse gear.  
(untensioned) (actuated)  
Engaged  
Engaged  
Blocked  
The transmission unit does not have a physical parking lock. By  
blocking the entire planetary gear set (annulus with planet carrier  
and sun gear in both directions), the gearbox is blocked; this serves  
as the parking lock function.  
(pre-loaded  
when rolling  
forwards)  
(not actuated)  
(when  
rolling  
back-  
wards)  
D1  
D2  
Closed  
Disengaged  
Blocked  
The planetary gear set serves as a speed reduction stage. The tor-  
que is transferred via the sun gear which is blocked by the free-  
wheel.  
(untensioned) (actuated)  
Open  
Engaged  
Freewheel The planetary gear set is blocked. Annulus, sun gear and planet  
carrier rotate at the same speed.  
(not actuated)  
Disengaged  
Recu- D1  
pera-  
tion  
Closed  
The planetary gear set serves as a speed reduction stage. The direc-  
tion of power flow is reversed. The torque is transferred via the sun  
gear which is blocked by the dog clutch.  
(pre-loaded) (actuated)  
D2  
Open  
Engaged  
Freewheel The planetary gear set is blocked. Annulus, sun gear and planet  
carrier rotate at the same speed.  
(not actuated)  
The direction of power flow is reversed without affecting the free-  
wheel.  
58  
Power flow  
Single-speed, D1, transmission  
684_200  
Key:  
Torque curve/power flow  
Blocked, stationary components  
Parts which co-rotate without being involved in power flow  
Engaged, blocked, engaged for power transmission  
Components joined to housing  
Clutch  
Power flow arrow  
Transmission po- Dog clutch  
Multi-plate clutch Freewheel Remarks  
Disengaged Blocked  
(untensioned) (actuated)  
sition/gear  
Drive D1  
Closed  
The planetary gear set serves as a speed reduction stage.  
The torque is transferred via the sun gear which is blocked  
by the freewheel.  
59  
Single-speed, D1, recuperation  
684_180  
Key:  
Torque curve/power flow  
Blocked, stationary components  
Parts which co-rotate without being involved in power flow  
Engaged, blocked, engaged for power transmission  
Components joined to housing  
Clutch  
Power flow arrow  
Transmission  
position/gear  
Dog clutch Multi-plate clutch Free-  
Remarks  
wheel  
Recuper- D1  
ation  
Closed  
Disengaged  
The planetary gear set serves as a speed reduction stage.  
The direction of power flow is reversed. The torque is trans-  
ferred via the sun gear which is blocked by the dog clutch.  
(pre-loaded) (actuated)  
60  
Reversing in 1st gear  
684_201  
Key:  
Torque curve/power flow  
Blocked, stationary components  
Parts which co-rotate without being involved in power flow  
Engaged, blocked, engaged for power transmission  
Components joined to housing  
Clutch  
Power flow arrow  
Transmis-  
sion posi-  
tion/gear  
Dog clutch Multi-plate  
clutch  
Free-  
wheel  
Remarks  
Drive R  
Engaged  
Disengaged  
Reverse gear is applied by reversing the direction of rotation of the  
electric motors. The planetary gear set of two-speed transmission  
0ME acts as a speed reduction stage in the same way as for 1st gear.  
The torque is transferred via the sun gear which is blocked by the dog  
clutch.  
(pre-loaded) (actuated)  
61  
2-speed, D2  
684_202  
Key:  
Torque curve/power flow  
Blocked, stationary components  
Parts which co-rotate without being involved in power flow  
Engaged, blocked, engaged for power transmission  
Components joined to housing  
Clutch  
Power flow arrow  
Planetary gear set in blocking mode/blocked  
62  
Transmission Dog  
Multi-plate clutch Freewheel Remarks  
position/  
gear  
clutch  
Drive  
D2  
Open  
Open  
Engaged  
Freewheel The planetary gear set is blocked. Annulus, sun gear and planet  
carrier rotate at the same speed.  
(not actuated)  
Engaged  
Recuper- D2  
ation  
Freewheel The planetary gear set is blocked. Annulus, sun gear and planet  
carrier rotate at the same speed. The direction of power flow is  
reversed without affecting the freewheel.  
(not actuated)  
As the planetary gear set is blocked by the multi-plate clutch, the torque is transmitted directly from the planet carrier to the annu-  
lus. The planetary gears and the sun gear do not affect the drive torque or the overrun torque during recuperation.  
The reversed direction of power flow during recuperation does not affect the freewheel.  
Transmission position P  
Parking lock function when rolling forwards  
684_203  
Transmission Dog clutch  
position/  
gear  
Multi-plate  
clutch  
Freewheel  
Remarks  
P
Engaged  
Engaged  
Blocked  
The transmission unit does not have a physical parking lock.  
By blocking the entire planetary gear set (annulus with  
planet carrier and sun gear in both directions), the gearbox  
is blocked; this serves as the parking lock function.  
(pre-loaded when (not actuated)  
rolling forwards)  
(when rolling  
backwards)  
63  
Parking lock function when rolling backwards  
684_204  
Key:  
Torque curve/power flow  
Blocked, stationary components  
Parts which co-rotate without being involved in power flow  
Engaged, blocked, engaged for power transmission  
Components joined to housing  
Clutch  
Power flow arrow  
Planetary gear set in blocking mode/blocked  
64  
Function diagram, 2-speed transmission 0ME  
65  
684_358  
Key:  
E313  
Selector lever  
G38  
Gearbox speed sender  
G79  
Accelerator position sender  
Gearbox oil temperature sender  
Brake pedal position sender  
Accelerator position sender 2  
Clutch position sender  
G93  
G100  
G185  
G476  
G836  
G1016  
GX2  
Brake pedal position sender 2  
Clutch jaw position sensor  
Accelerator pedal module  
J533  
J623  
J1235  
Data bus diagnostic interface  
Engine control unit  
Electric drive control unit for rear axle  
N486  
NX6  
Parking lock solenoid  
Brake servo  
V552  
VX65  
Gearbox auxiliary hydraulic pump  
Gear actuator  
Earth wire  
Positive wire  
LIN bus  
Sensor wire  
FlexRay  
FlexRay Low  
Sub-bus system (motor control unit CAN bus) High  
Sub-bus system (motor control unit CAN bus) Low  
CAN bus High (Infotainment)  
CAN bus Low (Infotainment)  
66  
Sensors  
Clutch position sender G476  
684_175  
Clutch position sender G476 helps register the shift state of the multi-plate clutch. It is bolted onto the gearbox housing from the  
outside. If repairs are required, only the bolts listed in the electronic parts catalogue (ETKA) for this purpose may be used.  
67  
684_437  
The shift state of the multi-plate clutch is registered indirectly based on the position of the release fork. The release fork is fitted  
with a bracket on which a small magnet is secured. This is used to register the position of the release fork. When the position of the  
release fork changes, the magnet moves along below clutch position sender G476.  
Clutch position sender G467 is supplied with current (approx. 5 V) by motor control unit J623. It registers the movement of the  
[5]  
magnet and uses it to generate a PWM signal . Using this signal, the motor control unit determines the shift state of the multi-  
plate clutch.  
The information regarding the shift state of the multi-plate clutch is also used to determine the state of the parking lock function  
(P-ON/P-OFF).  
If clutch position sender G476 fails, no gear changes take place during driving.  
If clutch position sender G476 is renewed, the function “Work steps after component replacement” must be carried out using the  
vehicle diagnostic tester via address word 0001 “Engine electronics, functions”.  
[5] PWM = pulse-width modulation  
68  
Sensor concept  
684_340  
Clutch position sender G476 works like a differential transformer. The centre part of the magnetically soft core is wrapped with a  
primary coil. The core has a secondary coil at each end which is wound in the opposite direction. The primary coil is supplied with  
alternating voltage, and thereby also induces alternating voltage in the secondary coil.  
When the magnet is in the centre of the sensor, the induced voltages in the secondary coils (wound in the opposite direction) can-  
cel each other out. If the magnet is pushed out of the centre, a difference in voltage arises at the secondary coils. The sensor elec-  
tronics use this to generate a PWM signal that corresponds to the position of the magnet.  
Reference  
For further information on this sensor concept, please refer to SSP 241 "The Audi allroad quattro with additional shift  
stage", starting on page 56.  
69  
Clutch jaw position sensor G1016  
684_328  
Clutch jaw position sensor G1016 registers the shift position of the dog clutch. It is bolted onto the gearbox housing from the out-  
side. If repairs are required, only the bolts listed in the electronic parts catalogue (ETKA) for this purpose may be used.  
684_327  
The position of the stator of the dog clutch is used to determine the shift state of the dog clutch. A small magnet is fitted on the  
stator for this purpose. When the position of the stator changes, the magnet moves along below clutch jaw position sensor G1016.  
70  
Sensor G1016 is supplied with current (approx. 5 V) by motor control unit J623. It registers the movement of the magnet and uses  
[5]  
it to generate a PWM signal . Using this signal, the motor control unit determines the shift state of the dog clutch.  
The information regarding the shift state of the dog clutch is also used to determine the state of the parking lock function (P-ON/P-  
OFF).  
If clutch jaw position sensor G1016 fails, no gear changes take place during driving. If clutch jaw position sensor G1016 is re-  
newed, the function “Work steps after component replacement” must be carried out using the vehicle diagnostic tester via address  
word 0001 “Engine electronics, functions”.  
Sensor concept  
Clutch jaw position sensor G1016 works in the same way as clutch position sender G476.  
Gearbox oil temperature sender G93  
684_353  
Gearbox oil temperature sender G93 measures the gear oil temperature in the oil pan and sends this information to motor control  
unit J623. The gear oil temperature measured is used to deduce the temperature of the multi-plate clutch.  
To ensure that the multi-plate clutch is cooled sufficiently, the delivery volume from the electric gear oil pump is varied according-  
ly.  
The table lists the measures that are carried out and the messages that are shown in the instrument cluster to protect the compo-  
nents and the gear oil at oil temperatures above approx. 110 °C.  
If sender G93 fails due to a defect, the delivery rate of gearbox auxiliary hydraulic pump V552 is increased accordingly, and the  
torque of the electric drive motor is reduced. In addition, the launch control function is not available.  
The instrument cluster shows the yellow warning lamp and the message:  
Gearbox malfunction: you can continue driving  
[5] PWM = pulse-width modulation  
71  
Oil temperature Measure  
Displays/messages  
Gearbox overheating: please adapt driving  
> 110 °C  
> 120 °C  
> 130 °C  
Torque of electric drive motor reduced. Launch control not  
available.  
style.  
Additionally, forced shift into 2nd gear with downshifting pro-  
hibited.  
Gearbox overheating: please adapt driving  
style.  
Maximum speed reduced additionally.  
Gearbox overheating: please stop vehicle  
Gearbox speed sender G38  
684_352  
Gearbox speed sender G38 helps the power electronics J1235 determine the following information:  
›
›
›
›
Gearbox output speed  
Direction of travel  
Slip in multi-plate clutch  
Target speed for gear change  
Speed sender G38 is composed of three Hall elements arranged in series, a permanent magnet and sensor electronics to generate a  
square wave signal. The large spur gear of the final drive acts as the sender wheel.  
The sender is supplied with a 5-Volt current by the power electronics J1235. The sensor electronics use the signals from the individ-  
ual Hall elements to determine the speed and direction of rotation of the gear wheel.  
The direction of rotation of the gear wheel is indicated by the duration of the square-wave signal.  
›
›
The signal duration when driving forwards is 120 μs  
The signal duration when reversing is 60 μs  
The speed of the gear wheel (proportional to the vehicle speed) is indicated on the basis of the frequency (f) with which the square-  
wave signal occurs. The frequency corresponds to the inverse value of the cycle duration (T).  
72  
At frequencies of 1000 Hz and above (which corresponds to a vehicle speed of approx. 75 km/h), the cycle duration is reduced to  
30 μs as a general rule.  
684_360  
684_421  
Measures if there is slip in the multi-plate clutch  
Motor control unit J623 receives information on the speed of the electric drive motor and the gearbox output speed of the power  
electronics J1235. It uses these two speeds to calculate the slip in the multi-plate clutch.  
The table lists the measures that are carried out and the messages that are shown in the instrument cluster if there is slip in the  
multi-plate clutch that should not be present (depending on the amount of slip):  
As the parking lock function is carried out in part by the multi-plate clutch, this function may not be available if there is too much  
slip in the clutch. If there is slip in the clutch, the transmission unit can no longer be used reliably to prevent the vehicle from roll-  
ing away.  
When the vehicle is stationary, the warning message Vehicle may roll away! P cannot be selected. Please apply parking appears in  
the instrument cluster, and the yellow warning lamp lights up.  
The vehicle can then be prevented from rolling away only by applying the parking brake.  
Clutch slip Measure  
Displays/messages  
Gearbox malfunction: you can continue driving  
Sporadic  
Torque of electric drive motor reduced.  
Constant Torque of electric drive motor reduced. Additionally: Forced  
shift back into 1st gear and therefore reduced maximum  
speed; upshifting prohibited.  
Gearbox malfunction: you can continue driving  
No parking lock function.  
Vehicle may roll away! P cannot be selected.  
Please apply parking brake  
73  
Oil system  
684_354  
Gearbox auxiliary hydraulic pump V552  
Gearbox auxiliary hydraulic pump V552 supplies the transmission with lubricating/cooling oil as required. The oil pump draws gear  
oil out of the oil pan via the suction filter and conveys the oil to all areas requiring lubrication via oil pressure lines and oil passages  
in the transmission housing.  
The pump consists of a brushless DC motor that drives an annular gear pump, as well as integrated power electronics. Motor con-  
trol unit J623 evaluates the amount of lubrication and cooling required for the current operating state, and uses this to determine  
the required pump speed.  
The information exchanged between motor control unit J623 and the oil pump is transmitted via a separate LIN bus.  
After the drive system is activated, the oil pump is actuated briefly to lubricate all the components. If the vehicle remains station-  
ary, the oil pump is actuated briefly approx. every 20 seconds, irrespective of the transmission position currently selected.  
As soon as the vehicle is driven, motor control unit J623 actuates the oil pump as necessary. The pump speed is regulated according  
to the following parameters:  
›
›
›
›
›
The calculated input torque of the transmission,  
The gearbox output speed,  
The selected gear,  
The oil pan temperature,  
The lateral/longitudinal acceleration of the vehicle  
Oil pump V552 sends a speed signal back to motor control unit J623 in a closed feedback loop. This allows the motor control unit  
to re-adjust the pump speed if necessary and ensure that the required amount of lubrication/cooling for the transmission is provi-  
ded.  
74  
If the pump speed drops when it should not, or if the pump fails, the following measure are taken:  
Cause  
Measure  
Displays/messages  
Slight drop in pump speed, Speed is re-adjusted  
e.g. oil filter dirty  
No display/messages  
Significant drop in pump  
speed  
Torque of electric drive motor reduced. Launch control not  
available.  
Gearbox: fault. Safely stop ve-  
hicle  
Additionally, forced shift into 2nd gear with downshifting pro-  
hibited and reduced maximum speed.  
No pump speed signal  
See “Significant drop in pump speed”  
Gearbox: fault. Safely stop ve-  
hicle  
Oil cooler  
684_355  
The gear oil cooler is an oil/coolant heat exchanger. It is integrated in the coolant circuit for the electric powertrain. There is no  
separate switching valve to decouple the oil cooler from the coolant circuit for the electric powertrain. If the electric drive motor  
and the power electronics for the rear axle are being cooled, the gear oil for the two-speed rear transmission unit is cooled auto-  
matically.  
75  
Oil filler and inspection plug and oil drain plugs  
684_356  
Two-speed transmission unit 0ME has two oil drain plugs to allow the oil to be drained completely. The hole for the oil filler plug is  
used to top up the oil and check the oil level. Please refer to the current workshop information for specifications on the oil capacity  
and oil type.  
Active rear axle differential lock  
684_357  
The Audi e-tron GT is available with an active rear axle differential lock as optional equipment. This differential lock is fitted as  
standard equipment on the Audi RS e-tron GT. The active differential lock can lock the speed equalisation function in the differen-  
tial as desired using a multi-plate clutch.  
Axle differential lock control unit J647 calculates the desired lock value and actuates axle differential lock motor V304 accordingly.  
The two axle differential lock Hall senders G460 and G461 and temperature sender G1175 are contained inside axle differential  
lock motor V304. The Hall senders allow axle differential lock control unit J647 to infer the position of the rotatable ball ramp ring,  
and the temperature sender provides information on the thermal load of the motor.  
76  
Depending on the desired lock value, axle differential lock motor V304 turns the adjusting ring for the clutch engagement mecha-  
nism via reduction gearing. The main components of the clutch engagement mechanism are a ball ramp ring, which can move  
along the shaft and is mounted so that it does not rotate, the ball bearings and a ball ramp ring that does rotate (referred to as the  
adjuster ring). The rotational movement of the adjusting ring creates axial movement which pushes the clutch plates together.  
The active differential lock works together with the selective wheel torque control of ABS control unit J104 to prevent the wheels  
from spinning.  
The two systems therefore improve:  
›
›
›
›
›
›
The torque distribution  
The traction  
The lateral acceleration potential  
The driving stability during changes in load when cornering  
The handling when changing lanes  
The stability in overrun phases  
This makes faster cornering speeds possible. The effect of the differential lock and any application of the brakes by the system are  
particularly noticeable when driving on surfaces that offer little traction, such as wet or snowy roads.  
In contrast to a conventional differential lock (see SSP 613 "Audi R8 Power Transmission", page 28), the active differential lock can  
be opened completely. This means that the rear brakes can be activated without interference if ABS control unit J104 intervenes.  
Note  
Axle differential lock control unit is fitted at the rear right inside the luggage compartment. If axle differential lock  
control unit J647 is renewed, the new control unit must be activated using the vehicle diagnostic tester. If axle differ-  
ential lock motor V304 is renewed, it must be adapted using the vehicle diagnostic tester to account for component  
tolerances.  
77  
684_350  
78  
Function diagram - active rear axle differential lock  
684_361  
Key:  
G460  
G461  
G1175  
Axle differential lock Hall sender 1  
Axle differential lock Hall sender 2  
Temperature sender for axle differential lock motor  
J233  
J533  
J623  
Adjustable rear spoiler control unit  
Data bus diagnostic interface  
Motor control unit  
79  
J647  
Axle differential lock control unit  
V304  
Axle differential lock motor  
Axle differential lock  
VX100  
T9c  
9-pin connector, grey  
T12u  
Electrical connector (12-pin); green  
Earth wire  
Positive wire  
Sensor wire  
Actuator wire  
FlexRay High  
FlexRay Low  
Service  
Towing the vehicle  
The vehicle must be transported on a breakdown truck (i.e. with all four wheels on the truck) or a special transporter.  
The vehicle must not be towed or push-started.  
Note  
Note the other descriptions and information on the topic of tow-starting and towing a trailer in the Owner's Manual.  
Gearbox warning/indicator lamps  
If the red transmission warning lamp appears in the instrument cluster, the driver is instructed not to drive any  
further.  
If the yellow transmission indicator lamp appears in the instrument cluster, it is generally possible to continue  
driving the vehicle. A corresponding driver message informs the driver of what to do.  
For detailed and up-to-date information, please refer to the Owner's Manual.  
Diagnosis  
Diagnosis is available for the electrical/electronic components and the control operations of two-speed transmission unit 0ME.  
The vehicle diagnostic tester can be used to access diagnostic results and carry out Guided Functions via address words “0001 En-  
gine electronics J623” and “0032 Lock electronics J647”.  
Some of the available functions are:  
0001 – Engine electronics J623  
0001 Electrical components  
0001 Engine electronics functions  
0001 Renew control unit  
0001 VX65 gear actuator  
Replace VX65 gear actuator  
0001 G467 clutch position sender  
Replace G467 clutch position sender  
Adapt G467 clutch position sender  
80  
0001 – Engine electronics J623  
0001 G1016 Clutch jaw position sensor  
Replace G1016 clutch jaw position sensor  
Adapt G1016 clutch jaw position sensor  
0001 Replace V552 gearbox auxiliary hydraulic pump  
0001 Work steps after exchanging components  
(Collection of various functions within address word 0001 that apply to exchanging components)  
0001 Gearbox functions  
Delete gearbox adaptions  
Adapt gearbox  
Replace gearbox  
0001 Read measured values  
0001 Activation - release of parking lock  
0001 Check control unit configuration  
0001 Query used vehicle info  
0001 Subsystems - boundary conditions  
0032 – Lock electronics J647  
0032 Electrical components  
0032 Lock electronics, functions  
0032 SVM control unit configuration  
0032 Read/erase event memory  
0032 Renew control unit  
0032 Identification  
0032 Read measured values  
0032 Basic setting  
(If replacing axle differential lock control unit J647 or the axle differential lock motor)  
0032 Subsystems - boundary conditions  
81  

Related Topics

Overview Selector mechanism Single-speed transmission ? 0MG Two-speed transmission 0ME Service

Popular Owner Manuals

Audi
Audi
BMW
BMW
Citroen
Citroen
Ford
Ford
Honda
Honda
Peugeot
Peugeot