V221 Hybrid

No testing to be performed on
active HV system connections.

PaigeE Learning & Performance 05-28-09

PaigeE Learning & Performance 05-28-09 S-Class Hybrid Technical Introduction 2
 High Voltage Components

HV Battery (A100)

HV Electric Motor (A79)

HV DC/DC Converter (N83/1)

HV Air Conditioning Compressor

(A9/5)

HV Power Electronics
control module (N129/1)

Note: Each high voltage component (except HV electric

motor) also has a 12 V control module within it,
that is connected to regular 12 V power supply.
PaigeE Learning & Performance 05-28-09 S-Class Hybrid Technical Introduction 3
 12 Volt Components

New brake pedal / booster

assembly (A7/7)

Additional electric transmission

oil pump (M42) & Control module
(N89)

Auxiliary vacuum pump (M56)

Regenerative Braking System (RBS)

control module (N30/6)

Electrohydraulic power steering

pump (A91/1)

Low temperature cooling system

pumps (M13/8 & M13/9)

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 Vehicle
Telematics CAN Chassis CAN
Dynamic CAN
(X30/35) (X30/30)
(X30/28)

Interior CAN
(X30/33)

Drive Train Sensor CAN

(X30/38)
Central CAN
(X30/20) Drive Train CAN
Interior CAN (X30/21)
Interior CAN (X30/32)
(X30/34)

Chassis CAN
(X30/31)

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High Voltage Battery (A100)
 HV Li-ion Battery (A100)
• Optimal charge % for Li-ion battery in display (instrument cluster or COMAND) is not
100%, instead it is around 50 – 65%.
• Battery management system control module will optimize charging to achieve the
optimal state of charge, do not expect to see 100%

A Critical low charge

B Low charge
C Optimal charge
D Critical upper charge
E State of charge (SOC) in %
U Voltage
1 Charging characteristic of electric
motor
2 Voltage characteristic of HV battery
3 Optimal operating state of charge

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Battery Management System (N82/2)
• Battery management system control unit (N82/2)
is integrated in the high-voltage battery assembly
• High-voltage battery assembly is located in the right
rear of the engine compartment
• The battery management system control unit
manages the high voltage power supply
• The battery management constantly determines
and monitors CAN network data as well as the
following high voltage battery data:
• High voltage interlock
• Voltage
• Current flow Note:
12 volt system battery with IBS system
• Temperature
for low voltage systems, similar to
• Status of contactors (A100s1) MY09 V221. 12 V battery in trunk with
Hybrid vehicle.

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HV Battery Cooling
• The battery management system (BMS) control module
monitors battery cell temperature through a series of
internal sensors
• The BMS will determine cooling requirements.
• BMS will control refrigerant flow through an internal
cooling circuit via the high voltage battery cooling shutoff
valve (Y19/1)
• Temperature sensors on the internal cooling circuit are
also used to determine operation of Y19/1
• BMS requests electric refrigerant compressor via CAN
• Step 1: BMS Æ ME Æ CGW Æ AAC
• Step 2: AAC evaluates request and determines if compressor can be engaged
• Step 3: AAC Æ CGW Æ ME Æ Electric refrigerant compressor
• Step 4: Electric refrigerant compressor receives request and confirms operation over CAN
• Step 5: With confirmation of compressor operation, BMS controls Y19/1

Note: Electric refrigerant compressor request has highest priority – customer cannot
switch off compressor using AC off button at this time.
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 HV Battery Cooling

1 Condenser A100 High-voltage battery assembly Y67 Rear air conditioning refrigerant
2 Fluid reservoir B10/6 Evaporator temperature sensor shutoff valve
3 Expansion valve B10/11 Rear air conditioning evaporator
temperature sensor A High pressure, gaseous
4 Evaporator B12 Refrigerant pressure sensor B High pressure, liquid
5 Rear air conditioning evaporator Y19/1 High-voltage battery cooling system C Low pressure, liquid
A9/5 Electric refrigerant compressor shutoff valve D Low pressure, gaseous
PaigeE Learning & Performance 05-28-09 S-Class Hybrid Technical Introduction 10
Power Down / Up High Voltage
System
Power Down (Deactivation)
In order to work on or near hybrid high voltage components the high voltage
system must be powered down (deactivated) by a qualified person that has
successfully completed the required training

• When working on any high voltage system it is mandatory to follow

all safety rules and steps, for example:

• Provide a barrier around the vehicle

• Maintain control of ignition key and ignition position in vehicle
• Follow sequence of steps in deactivation log / work instructions in DAS
• Use protective gloves when appropriate (always check their date and condition)
• Remove DC-DC high voltage connection & secure service disconnect switch tool
• Secure service disconnect key (do not leave key in service disconnect switch tool)
• Ensure voltage free and print out document “deactivation log” with DAS
• Sign and post the print-out of the deactivation log so it is visible in the vehicle

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Power Up (Initial Start up)
In order to power up (initial start up) components of the high voltage system,
a qualified person that has successfully completed the required training must
complete this task.

• When working on any high voltage system it is mandatory to follow

all safety rules and steps, for example:

• Provide a barrier around the vehicle

• Maintain control of ignition key and ignition position in vehicle
• Follow sequence of steps in initial start up log / work instructions in DAS
• Remove service disconnect switch tool and reconnect DC-DC high voltage cable
• Ensure high voltage system activated and print out document “initial start up log” with DAS
• Sign and print out document “initial startup log” with DAS
• Remove deactivation log from vehicle
• Both log printouts are to be attached to Repair Order
• Remove barrier and safety equipment if appropriate and store correctly
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 Electric Motor (A79)
& Rotor Sensor (L20)
High Voltage Electric Motor (A79)
• The electric motor is installed between
the engine and automatic transmission.
• It performs the function of a starter and
high-voltage alternator.
• Switching between the individual
operating modes (motor mode /
alternator mode) is controlled by
the power electronics control unit.
• Maximum boost (motor mode)
output = 15 kW (20 hp)
• Maximum charging (alternator mode)
output – 17 kW 1 Stator carrier
2 Rotor with increment ring and position sensor track
3 Intermediate housing
4 Stator with coils
5 Connection and temperature sensor coupling
L20 Rotor position sensor

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High Voltage Electric Motor (A79)
• Power electronics control unit monitors
a temperature sensor integrated in the
stator windings
• Power electronics control unit will
reduce power output, if a certain
temperature threshold is exceeded
in order to protect the electric
motor from overheating
• Power limitation will begin when stator
winding temperature exceed factory
specification
• 2 position sensors are installed 1 Stator with coils
• B70; crankshaft Hall speed sensor 1/1 Connection and temperature sensor coupling
for ME 2 Stator carrier
3 Rotor with increment ring and position sensor track
• L20; rotor position sensor 4 Intermediate housing
for power electronics B70 Crankshaft Hall sensor
L20 Rotor position sensor
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Rotor Position Sensor (L20)
• Detects speed, rotation direction and
position of the rotor ring
• L20 sensor operates on the Eddy current
principle
• This particular Eddy current sensor
consist of:
• 2 transmitting sensor heads
• 2 receiving sensor heads
• The transmitter sensor head produces a
magnetic field
• The passing component (rotor) sensor
track disrupts the magnetic field
• The receiving sensor head reads the
magnetic field
• In this application a sine or cosine signal
pattern is produced due to the shape, and
position of the sensor heads & sensor track
• Operates using 5 volt reference value
Raised sensor track on rotor ring

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Engine M272.974
 Engine
General: 3.5 liter V6 gasoline

Type: M272.974
Valves: 4 per cylinder
Displacement: 3498 cc
Compression Ratio: 10.7 : 1
Power: 279 hp @ 6000

Torque: 350 Nm @ 2,400 – 5000

Note:
Engine 272 has been modified and optimized for the hybrid
application:
- Atkinson principle
Atkinson Principle: - M272 SPORT cylinder heads
The development engineers utilized some of the - Standard M272 intake manifold (no actuation of
benefits of the Atkinson principle whereby the tumble flaps)
expansion phase is longer than the compression - Modified camshafts with a different camshaft
phase. The intake valve is kept open slightly control system
longer between the intake and compression - M272 SPORT pistons.
phases, which improves the engine's thermal - Regulated output oil pump, to reduce engine load
efficiency while reducing the specific fuel - New fuel management version (ME 17.7)
consumption and untreated emissions.

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 M272.974 - Power and Torque Chart
A Electric motor performance
B Combustion engine performance
C Maximum power combined (electric
motor and combustion engine)
D Electric motor torque
E Combustion engine torque
F Maximum torque combined
(electric motor and combustion
engine)

M Torque
n Engine speed
P Power

Nm lb ft kW hp
400 295 210 281
350 258 70 94
300 221 40 54
250 184 20 26

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 Engine Oil Pump Valve (Y130)
• Under certain conditions the power required to
operate the mechanical engine oil pump can be
reduced by regulating the oil volume
• For example at idle, no load conditions
• Although a small change, it is another measure to
improve fuel economy
• A engine oil pump valve (Y130), is installed to
regulate oil volume
• Engine oil pump valve (Y130), is located close to the
front pulley on the engine
• ME-SFI (N3/10) controls the valve according to
engine load demands

Mirror used to see from above

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Regenerative Braking System
(RBS)
Regenerative Braking System
• The regenerative braking system (RBS), is a brake by-wire Hybrid variation of
Adaptive Brake Regulation (ABR), known from V221
• Hybrid vehicles take advantage of utilizing the same electric motor used for
engine boost, to charge high voltage system
• This charging function occurs whenever the engine is running or the vehicle is
coasting or braking
• In the case of braking, the RBS will request regulation of the electric motor to
generate electricity
• This regulation not only produces electricity but also provides a braking reaction
through the drive train
• The amount of regulation provided by the electric motor is communicated back to
RBS, where it can determine the correct amount of hydraulic brake regulation to
compliment the electric motors braking effect

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 RBS Component Overview
B18/5
A7/7b3
A7/3 Traction system hydraulic unit
A7/7 RBS brake booster
A7/7b1 RBS Membrane travel sensor
A7/7b3 Vacuum sensor
A7/7y1 RBS solenoid valve
A79 Electric motor
B18/5 Pressure sensor for pedal force
simulator valve (not shown)
B37/1 Pedal angle sensor
N30/6 Regenerative braking system
(RBS) control unit
N129/1 Power electronics control unit
Y113 Pedal force simulator valve

1 Pedal movement
A7/7b1
2 Travel at pedal force simulator
3 Free travel

Typical RBS representation

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RBS Animation

Typical RBS representation

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Regenerative Braking System (RBS)
• The RBS solenoid valve (A7/7y1) in the
brake booster (A7/7) is modulated by the
regenerative braking system (RBS) control
unit in accordance with driver braking
request

• Through the modulation of this solenoid valve

the master cylinder piston rod is actuated

• The hydraulic braking system functions as

before utilizing the available vacuum in the
brake booster
4 Electrical connection for A7/7y1
A7/7 Brake booster
A7/7y1 RBS solenoid valve

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Electric Vacuum Pump
• Located on left side of engine above electric
refrigerant compressor
• Ensure adequate vacuum in RBS brake booster
• Maintain vacuum supply during start-stop
operation
• Pressure sensor in brake booster reports
available vacuum in brake booster to RBS
control unit
• RBS control unit actuates electric vacuum
pump as required via two relays:
• K109 – power side
• K109/1 – ground side
• Relays are located next to the AIRMATIC
air tank, left front

Location: Left front frame rail

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 Special Tools

These eyelets together with the engine hoist and engine crane must Required to disassemble/assemble the elastic permanent ribbed
be used for the removal/installation of the HV battery (weight 40kg - V-belt (stretch fit belt). To remove/install belts, a clamp is
100kg) in hybrid vehicles. The ring bolts have a defined thread length fastened onto the belt pulley. Rotating the crankshaft enables the
of 13mm. It is mandatory to maintain this thread length. If a longer ribbed belt to be lifted off the belt pulley without damaging it
thread length is used the battery cells of the HV battery will be (without any overstretching and twisting). It is fitted in the reverse
damaged and the HV battery will be unusable. order. The use of assembly levers or other prying tools will cause
damage to the belt pulley and ribbed belt.

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 Special Tools

For safety reasons, vehicle must not carry any voltage (0V) while work To release the crankshaft's center bolt (e.g. replacement of
is being conducted on it (e.g. hybrid vehicles). To prevent any crankshaft radial sealing ring) the vibration damper on this engine
unauthorized reactivation of the system thereby putting people at risk, has to be held steady. This major assembly is equipped with 2
a lockable safety plug is fitted to the connecting point. This serves to stretch fit belts on the vibration damper, which is why the working
ensure that only those people can put the vehicle back into service surface for the counter holder is seated very low in the vibration
who are authorized to do so. damper. For this reason, existing counter holders cannot be used
on this engine.

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 HV Battery Transport / Disposal
IMPORTANT:
An HV battery that has been dropped from a height of more
than 21 inches (50 cm) must be disposed of.

The Li-ion HV battery is classed as hazardous material in

international dangerous goods regulations.
The HV battery must be transported under the correct
classification according to country or states rules:
E.g. - UN 3480 Lithium-ion battery, Class 9, PG II.

A used battery is safe for transport if the following are met:

¾ No cracks or significant deformation in the battery housing
¾ No electrolyte leaking from the battery or No free electrolyte
in the battery
¾ No danger of the battery overheating or development of fires
during transport
¾ No danger resulting from internal or external short circuits.
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