627_007

Special high voltage battery identification label
This adhesive label is affixed to the top of the high voltage
battery, both in English and in the import country's national
language.

*DIN - Deutsches Institut für Normung. A standards defining organization. Similar in function to the SAE.

7

Battery Regulation
The High Voltage system in the A3 e-tron is shut down and
electrically isolated if any of the following conditions are met:
•
•
•
•

Terminal 15 switched off.
A crash signal from the Airbag Control Module is detected.
Maintenance connector TW is opened.
Fuse for power supply to power contactors terminal 30c is
disconnected.
• 12 volt power supply for the Hybrid Battery Unit is interrupted.
• Safety line open.

Safety line
The safety line is a 12 volt ring wire which interconnects all
high voltage components in series. The Battery Regulation
Control Module inputs an electrical current of approximately 10 mA into the safety line and evaluates the current
flow. In addition, the Electrical Drive Control Module monitors the safety line.
If the safety line is broken, the high voltage system is
immediately deactivated by the Battery Regulation Control
Module. The high voltage contacts are opened. The driver is
notified via the display in the instrument cluster.

627_037

8

High voltage lines
Single-pole high voltage line

All high voltage lines in the high voltage system are are
color-coded orange for identification. Due to the high
voltages and currents involved, the electrical lines have a
significantly larger cross-section and are connected by
special plug-in contacts. The electrical lines of the high
voltage system differ from the other lines in the 12-volt
electrical system in terms of their core design.

Conductor
Insulation

Shielding

The high voltage lines may also have a corrugated plastic
tube to provide protection against chafing. Three different
types of high voltage line are used in the high voltage
system: single-pole and 2-pole lines with and without a
safety line.

Insulation

627_052

2-pole high voltage line
With safety line
Insulation

Without safety line
Shielding

Shielding

Insulation

HV positive

Safety line

HV negative
627_054

627_053

High voltage connections
The high voltage lines on the Audi A3 Sportback e-tron are
bolted onto or plugged into the high voltage components.

To avoid incorrect assembly, all connections are mechanically encoded.

Bolted connection

2-pole plug connection

627_055

627_056

9

High Voltage System Maintenance Connector
The High Voltage Electrical System Maintenance Connector
is located in the engine compartment. It serves as an
electrical connection in the 12 volt control circuit for the
high voltage battery contacts and as a component part of
the safety line.
Opening the High-voltage Electrical System Maintenance
Connector opens the safety line and breaks the 12 volt
control circuit of the high voltage power contacts, this
serves to de-energize the high voltage system.
The VAS Scan Tool must be used to properly de-energize the
high voltage system. After the High-voltage Electrical
System Maintenance Connector is opened, it must be
secured with padlock (special part number T40262/1) to
prevent it from being accidentally reconnected.
In the engine compartment

627_057

The maintenance connector is labelled.

627_058

Fuse panel in passenger compartment
The power supply fuse for the control circuit of the power
contacts is labelled. This fuse is to be utilized by first
responders in an emergency situation.

627_059

627_060

Information
After de-energizing the system, a check must be made to ensure that no voltage is present by running the relevant Test Plan
in ODIS Service.
10

Drive unit
Specifications
Torque-power curve

EA211 series 1.4l TFSI engine CUKB

Torque in Nm

Power in hp

Internal combustion engine

Internal combustion engine

Electric motor

Electric motor

System (15 seconds)

System (15 seconds)

295.0 lb ft (400 Nm)

268.2 hp (200 kW)

258.1 lb ft (350 Nm)

234.6 hp (175 kW)

221.21 lb ft (300 Nm)

201.1 hp (150 kW)

184.3 lb ft (250 Nm)

167.6 hp (125 kW)

147.5 lb ft (200 Nm)

134.1 hp (100 kW)

110.6 lb ft (150 Nm)

100.5 hp (75 kW)

73.7 lb ft (100 Nm)

67 hp (50 kW)

36.8 lb ft (50 Nm)

33.5 hp (25 kW)

Engine speed [rpm]

627_093

11

Internal combustion engine and e-machine with transmission

Electro-drive Drive Motor (e-machine)

6-speed dual clutch transmission
(S tronic)

627_107

1.4l TFSI engine

Features

Specifications

Engine code

CUKB

Type

Four-cylinder in-line engine

Internal combustion engine output

150 hp (110 kW) at 5000 - 6000 rpm

Electric motor output

102 hp (75 kW) at 2000 - 2300 rpm

System output

150 kW

Torque of internal combustion engine

184 lb ft (250 Nm) at 1600 - 3500 rpm

Electric motor torque

243 lb ft (330 Nm) at 2200 rpm

System torque

258 lb ft (350 Nm)

Displacement in cm

1395

Stroke

3.1 in (80 mm)

Bore

2.9 in (74.5 mm)

Number of valves per cylinder

4

Firing order

1–3–4–2

Compression ratio

10 : 1

Fuel type

Premium 91 AKI

Turbocharging

Exhaust turbocharger

Engine management system

Bosch MED 17.01.21

Powertrain type

6-speed dual clutch transmission (S tronic)

Oxygen sensor control

1 sensor upstream of catalytic converter and 1 sensor downstream of catalytic converter

Mixture formation

Direct injection

Emission standard

SULEV 30

3

12

Internal combustion engine
The A3 Sportback e-tron uses the series 1.4l engine.
Because the transmission is 2.26 in (57.5 mm) longer to
accommodate the e-machine, the engine is mounted
further to the right than in the standard A3 Sportback.
The main bearings, the connecting rod big end bearings
and the piston rings of this engine have special coatings. In
addition, piston backlash has been adapted and the cylinder liners are plasma-coated.

During electric-only driving, the internal combustion
engine can start in order to heat up the catalytic converter.
To ensure wear-free starting of the internal combustion
engine after electric-only operation, clutch K0 closes and
the e-machine turns the engine over until sufficient oil
pressure is obtained.
In the U.S. market, the engine is also equipped with secondary air injection.

The Audi A3 Sportback e-tron can be driven in electric-only
mode. This can result in periods of time during which the
internal combustion engine is not in use.

627_023

Engine start
The internal combustion engine is started by the e-machine.
The engine Control Module sends a start message to the
Transmission Mechatronic Module. Clutch K0 is closed and
connects the e-machine rotor to the internal combustion
engine’s crankshaft. The rotor brings the engine’s crankshaft up to starting speed. The engine control module then
enables the ignition and fuel injection and the engine
starts.

If it is necessary for the internal combustion engine to start
when the vehicle is running in electric-only mode, the torque
from the e-machine is increased by the amount necessary to
start the internal combustion engine when the clutch closes.
This prevents judder. After starting, clutch K0 is opened and
the internal combustion engine runs at no load. After the
speed of the internal combustion engine has been adapted
to that of the e-machine, clutch K0 is closed again.

13

Brief technical description

Cylinder block

• Four-cylinder in-line engine.

The cylinder block is made of die-cast aluminum and is an
open-deck design. The advantages and disadvantages of an
open-deck design are:

• Four valves per cylinder, double overhead camshafts
(DOHC).
• FSI direct injection.
• Cast aluminium cylinder block.
• Turbocharger with indirect intercooler.
• Intercooler integrated in intake manifold
(air/coolant heat exchanger).
• Belt driven camshafts.
• Emission control system with ceramic catalytic converter
and converter heating function using two-stage injection
(homogeneity split).

• It is easier and more economical to manufacture from
the point of view of casting technology.
• More efficient cooling of the upper, (and hotter) part of
the cylinders compared with a closed-deck design

1.4l TFSI engine
(Engine with cylinder selective shut-down shown)

Aluminum cylinder block
with open-deck design

Main crankshaft bearings

Oil baffle plate

Sump top section

Oil Level Thermal Sensor

Sump bottom section

616_014
14

Intercooler
After the intake air has passed through the turbocharger, it
is very hot. It is heated up to temperatures as high as 392 °F
(200 °C)., mainly due to the compression process, but also
because the turbocharger itself is very hot.
To cool the air from the turbocharger, it is passed through
an intercooler, which is integrated in the intake manifold
module.

The intercooler is an air/coolant heat exchanger and incorporated in the engine’s coolant circulation system.
The hot air flows over the fins and the heat of the air is
passed to the fins. The fins transfer the heat to the
coolant. The heated coolant is pumped to the intercooler
system’s auxiliary radiator where it is cooled down again.

Heated air in turbocharger
outlet pipe

Turbocharger

Charge Air Pressure Sensor
G31 and Intake Air
Temperature Sensor 2

Intercooler

Cooled charge air

Heated coolant to intercooler
radiator in front end

Intake manifold

Cooled coolant from intercooler
radiator in front end

Air filter box mounted directly
on engine

Air Intake
The air intake system is on the forward facing side of the
engine. The air filter box is mounted directly on the engine.
The intercooler is integrated in the injection-molded plastic
intake manifold. The advantage of this is that the relatively
small volume of air in the entire charge air tract can be
quickly compressed. Very rapid pressure generation and
very responsive engine performance are the results. The
distance travelled by the charge air from the impeller to
the intake manifold module through the plastic intake pipe
(turbocharger outlet pipe) is also very short.
15

Turbocharger
Because the exhaust manifold is integrated in the cylinder
head and has its own coolant jacket, it is possible to use a
very lightweight mono-scroll turbocharger.

Mono-scroll turbochargers have only one inlet helix which
directs the exhaust to the turbine rotor. The significant
advantage is their simplicity of design, which makes monoscroll
turbochargers especially light and economical.

Turbocharger outlet pipe

Intake manifold from air filter

Non-return valve for inlet from
crankcase venting system

Wastegate

Charge Air Pressure Actuator

Connecting flange to
cylinder head

Wastegate actuating lever
616_041

16

Fuel system
Because hydrocarbons also form when the vehicle is driven in
electric-only mode, there is a danger of overloading the
activated charcoal filter (carbon canister). To prevent this, the
A3 Sportback e-tron is equipped with a pressure reservoir.

During electric-only driving, the line leading to the carbon
canister is closed by the Tank Switch-off Valve. The pressure
in the fuel tank then increases to approximately 4.3 psi
(0.3 bar). The pressure is measured by the Fuel Tank Pressure Sensor and relayed to the ECM.

Tank Switch-off Valve

Fuel Tank Pressure Sensor

627_094

Fuel Filler Door Release Button

Fuel filler flap
The fuel filler flap of the A3 Sportback e-tron is locked and
cannot be opened by hand until the pressure in the fuel
tank has dropped. This only takes a few seconds.
When the driver actuates the Fuel Filler Door Release
Button on the driver’s door panel, the ECM opens the Tank
Shut-off Valve. The reduction in pressure is detected by the
Fuel Tank Pressure Sensor. The Vehicle Electrical System
Control Module 1 then automatically opens the fuel filler
flap.
The status of the fuel filler flap is indicated in the DIS.
627_095