Husqvarna AUTOMOWER 550 Instruction manual

Husqvarna Automower®550 EPOS, 550H EPOS
Workshop manual

Contents
1 Introduction
1.1 Document description............................................ 3
1.2 Servicing tools........................................................3
1.3 Technical data........................................................3
2 Safety
2.1 Safety definitions....................................................4
2.2 General safety instructions.....................................4
2.3 Special safety instructions......................................4
2.4 Symbols on the product......................................... 4
3 System description
3.1 System overview.................................................... 5
3.2 Satellite signals and radio signals.......................... 5
3.3 Real-time kinematic (RTK)..................................... 5
4 Product and installation
4.1 Main components for installation............................6
4.2 Charging station..................................................... 6
4.3 Circuit boards and sensors ................................... 6
4.4 Reference station................................................... 7
5 Autocheck service tool
5.1 Installation and login.............................................. 9
5.2 Product connections...............................................9
5.3 To connect the product with USB service cable.....9
5.4 To connect to the product with Bluetooth®.............9
5.5 How to use Autocheck 3...................................... 10
5.6 Programming a new application circuit board...... 10
5.7 Demo mode..........................................................11
5.8 To recover the PIN code...................................... 11
6 Repair instructions
6.1 Product overview..................................................12
6.2 To mount screws..................................................13
6.3 To remove and install the body............................ 13
6.4 To remove and install the upper chassis .............14
6.5 To remove and install the center console............ 15
6.6 To replace the top cover ..................................... 16
6.7 To replace the rear bumper..................................16
6.8 To replace the front bumper 550H EPOS............ 16
6.9 To replace the headlights ....................................17
6.10 To replace the buzzer........................................ 17
6.11 To replace the main switch................................ 17
6.12 To clean and replace the ventilation filter...........17
6.13 To replace the front joysticks............................. 18
6.14 To replace the rear joysticks.............................. 19
6.15 To replace the START/STOP button .................19
6.16 The circuit boards and sensors.......................... 20
6.17 The battery system.............................................25
6.18 The cutting system............................................. 26
6.19 The wheel motors...............................................28
6.20 Charging station................................................. 30
6.21 To mount screws in plastic.................................31
6.22 To mount thread plugs....................................... 32
6.23 To replace the sealing strip................................ 32
7 Service
7.1 Service schedule..................................................34
7.2 Screw fasteners................................................... 35
8 Troubleshooting
8.1 Messages.............................................................37
8.2 Symptoms............................................................ 45
8.3 LED indicator lamp on the charging station......... 47
8.4 Battery test........................................................... 48
9 Transportation, storage and disposal
9.1 Transportation...................................................... 49
9.2 Cleaning............................................................... 49
9.3 Winter storage......................................................49
9.4 Environmental information................................... 49
9.5 Removal of battery for recycling...........................49
21541 - 001 -

1 Introduction
1.1 Document description
The Workshop manual is intended for dealers and
service personnel, and is a supplement to the Operator’s
Manual. The following system is used in Workshop
manual to make it easier to use:
• Text written in italics is a text that is shown in the
Automower® Connect app or in the menus in the
Autocheck service program.
• Text written in bold is one of the buttons on the
product or in the menus of the Autocheck service
program.
• Text written in UPPERCASE and italics refer to the
position of the main switch and the different
operating modes available in the product.
1.2 Servicing tools
Always use original tools recommended by the
manufacturer.
1.3 Technical data
For the technical data, refer to Operator's manual and
the manufacturer's website.
1541 - 001 - Introduction - 3

2 Safety
2.1 Safety definitions
Warnings, cautions and notes are used to point out
specially important parts of the manual.
WARNING: Used if there is a risk of injury or
death for the operator or bystanders if the
instructions in the manual are not obeyed.
CAUTION: Used if there is a risk of damage to
the product, other materials or the adjacent area
if the instructions in the manual are not obeyed.
Note: Used to give more information that is necessary in
a given situation.
2.2 General safety instructions
WARNING: Keep your hands and feet away
from the rotating blades. Never put your hands
or feet close to or under the machine when the
motor is running.
WARNING: Apply a new warning label if a
warning symbol on the product is damaged or
missing.
WARNING: The original design of the product
must not be modified without the expressed
permission of the manufacturer.
Unauthorized modifications and/or components
can result in serious disruptions and the risk of
personal injuries.
Only use original spare parts.
2.3 Special safety instructions
2.3.1 Maintenance
WARNING: The product must be switched off
before any maintenance is done.
CAUTION: Never use a high-pressure washer
to clean the product. Never use solvents for
cleaning.
2.3.2 In the event of a thunderstorm
If there is a risk of a thunderstorm, all connections to the
charging station must be disconnected. This is done to
avoid damage to the circuit board in the charging
station.
2.3.3 Battery safety
WARNING: Lithium-ion batteries can explode or
cause fire if disassembled, short-circuited,
exposed to water, fire, or high temperatures.
Handle carefully, do not dismantle, open the
battery or use any type of electrical/mechanical
abuse. Avoid storage in direct sunlight.
For more information about the battery, refer to
Technical data in the Operator's manual.
2.4 Symbols on the product
These symbols can be found on the product. Study them
carefully.
WARNING: Read the user in-
structions before operating
the product.
WARNING: Disable the prod-
uct before working on or lifting
the product.
WARNING: Keep a safe dis-
tance from the product when
operating. Keep your hands
and feet away from the rotat-
ing blades.
WARNING: Do not ride on the
product. Never put your
hands or feet close to or un-
der the product.
Use a detachable power sup-
ply as defined on the rating la-
bel next to the symbol.
This product conforms to the
applicable EC Directives.
It is not permitted to dispose this product
as normal household waste. Ensure that
the product is recycled in accordance with
local legal requirements.
The low voltage cable must not be
shortened, extended or spliced.
Do not use a trimmer nearby the low
voltage cable. Be careful when trimming
edges where the cables are placed.
4 - Safety 1541 - 001 -

3 System description
The EPOS system contains a robotic lawn mower, a
charging station and a reference station. The robotic
lawn mower and the reference station receive satellite
signals for positioning. The reference station is
stationary and sends correction data to the robotic lawn
mower to get an accurate position of the robotic lawn
mower. The work area for the product is made virtually
in Automower® Connect app by operating the product
and adding waypoints to make a map in the app. Refer
to System overview on page 5 .
3.1 System overview
5
3
1
2
8
8
2
4
9
6
10
11
7
6
1. Navigation satellites
2. Satellite signals
3. Reference station1
4. Correction data
5. Charging station
6. Virtual boundary
7. Stay-out zone
8. Work area
9. Mobile device2
10. Docking point
11. Transport path
3.2 Satellite signals and radio signals
The global navigation systems (GNSS) that are used are
GPS, GLONASS, Galileo and BeiDou. Position in the
world, time of the day, season, weather, direction,
satellites or an obscured view between the mower and
the reference station can have an effect on the signals.
3.3 Real-time kinematic (RTK)
Real-time kinematic (RTK) positioning is a satellite
navigation technology used to increase the precision of
position data from satellite based position systems. The
product receives real-time corrections from a reference
station. The accuracy is on centimeter level.
1Purchased separately.
2Not included.
1541 - 001 - System description - 5

4 Product and installation
4.1 Main components for installation
The robotic system involves these main components:
• Product
• Charging station
• Power supply for charging station
• Reference station
• Power supply for reference station
Go to the manufacturer's website or read the Operator's
manual for further descriptions about the product and
the installation.
4.2 Charging station
The placement of the charging station must be well
planned in order to give the best installation and
operation of the product. Refer to Installation - To
examine where to put the charging station in the
Operator’s Manual.
Note: The battery is spared if charged in the lowest
possible ambient temperature. Consequently, it is
beneficial if the charging station is placed where it is
shaded, especially during the warmest parts of the day.
When the battery level has decreased to 15% state of
charge, approximately 17.25V, the product stops the
blade motor and starts to search for the charging station.
4.2.1 Charging station signal
The charging station transmits the signals that follow:
FN
D
• F signal, is given by a loop in the charging station so
that the product knows that it is near the charging
station. The signal includes the signal for the pairing
of charging station and the product.
• N signal, is given by a loop in the charging station
baseplate to guide the product correctly into the
charging station.
• The docking point (D) is where the product changes
between the F/N field and the EPOS system for
navigation. The product always goes to the docking
point before entering the charging station and
reverses to that point when it exits the charging
station.
4.2.2 LED indicator lamp on the charging station
The status of the charging station is easily checked
using the LED indicator lamp on the charging station.
Refer to LED indicator lamp on the charging station on
page 47 .
4.3 Circuit boards and sensors
The circuit boards and sensors in the product:
7
5
2
8
9
1
6
4
10
11
7
5
3
1. Motor control circuit board (rear loop sensors and tilt
sensor)
2. RTK module
3. Application circuit board
4. Communication circuit board
5. Ultrasonic sensors
6. Front loop circuit board (front loop sensors)
7. Lift sensor circuit board (lift sensors)
8. Front collision circuit board (front collision sensor)
9. Rear collision circuit board (rear collision sensor)
10. Cutting height circuit board (cutting height sensor)
11. Ultrasonic circuit board
CAUTION: Some sensors contain a hall sensor
and a magnet. Because of the magnets south
and north pole, it is important that the magnet is
correctly installed.
6 - Product and installation 1541 - 001 -

4.3.1 Motor control circuit board
The motor control circuit board controls the cutting
motor, the height adjustment motor and the wheel
motors. The main switch, USB contact, rear loop
sensors and tilt sensors are located on the motor control
circuit board.
4.3.1.1 Rear loop sensors
The loop sensors measure the signals in the charging
station baseplate (F signal). The signals are used to
control the product when it is near the charging station
and when entering the station. The product can only
sense the signals if it has been paired with the charging
station.
4.3.1.2 Tilt sensor
The tilt sensor is a sensor on the motor control circuit
board that senses the product’s inclination in relation to
the horizontal plane. The X-angle shows the front to rear
inclination, and the Y-angle shows left to right
inclination. The value from the tilt sensor is used, among
other things, to correct the speed of the drive wheels
when cutting in steep slopes. Make sure that the product
is put on a horizontal surface when calibrating the
sensor to get correct values.
4.3.2 RTK module
The RTK module contains the radio circuit board and the
GNSS circuit board. The radio circuit board has a radio
module and an antenna. It communicates with the
reference station using radio signals and receives
correction data from the reference station. The GNSS
circuit board includes the GNSS module with high
precision positioning. It is used for all position
information used by the product, such as GeoFence and
navigation.
4.3.3 Application circuit board
The application circuit board is the primary board in the
product. It stores the mower settings, including maps
and schedules. The product serial number and PIN code
are also stored at the application circuit board. The
application circuit board contains the Bluetooth®
module.
4.3.3.1 Bluetooth®
Bluetooth® uses short-range communication with the
Automower® Connect app. When a mobile device, that
is paired with the product, is within the Bluetooth® range
it is the primary communication between the product and
the app. Some functions and menus are only available
with Bluetooth® communication. Security, appDrive,
installation of map, edit map and to enter the PIN code
are some examples.
4.3.4 Communication circuit board
The communication circuit board uses cellular
communication with the Automower® Connect app,
Husqvarna Fleet Services™ and also to download
firmware through FOTA. Maps and data are uploaded to
the cloud through FOTA so that it can be transferred to a
replacement mower or a replaced application circuit
board.
4.3.5 Ultrasonic circuit board
The ultrasonic sensors are used to read off the distance
to obstructions in front of the mower. If an obstruction is
detected, the mower will slow down before it collides
with it. The signals are received by the sensors located
in the body and are processed by the ultrasonic circuit
board inside the chassis.
4.3.6 Front loop circuit board
The front loop circuit board contains the front loop
sensors for the product.
4.3.6.1 Front loop sensors
See rear loop sensors, refer to
Rear loop sensors on
page 7 .
4.3.7 Lift sensor circuit board
The lift sensors detect if the product is being lifted off the
ground. This is done with the help of the mechanical
design and magnets. If a lift signal is indicated, the blade
disc stops immediately. The product tries extrication
maneuvers by reversing and turning several times.
4.3.8 Front/rear collision sensor circuit board
The collision sensors are the sensors that detect when
the product has run into a fixed object. When the
sensors are activated, the product stops and moves
rearwards and then turn to continue in a different
direction.
4.3.9 Cutting height circuit board
The cutting height sensor detects the position of the
blade disc and is used when adjusting the cutting height.
The cutting height sensor must be calibrated to obtain
the correct cutting height. The cutting height sensor is
regularly calibrated automatically.
4.3.10 STOP sensor
There is a micro switch in the STOP button that detects
if the STOP button is pushed down. If the STOP signal
is indicated, the product and the blade disc stop
immediately.
4.4 Reference station
For detailed information about the reference station,
refer to Workshop manual for the reference station .
To replace the reference station in an installation, make
sure that the new reference station is installed at the
1541 - 001 - Product and installation - 7

same position in the same area so that the maps are not
affected. Enter the Automower® Connect app and
remove the old reference station and pair with the new
one. If the reference station is moved from its original
position all maps must to be reinstalled.
8 - Product and installation 1541 - 001 -

5 Autocheck service tool
Autocheck 3 is a PC tool developed for the service of
the robotic lawn mowers from Husqvarna Group. It is a
tool for troubleshooting as well as a database of sold
products and service history. Autocheck also includes
technical documentation and service bulletins.
Autocheck 3 supports all G3 (Generation 3) and G4
(Generation 4) products. Autocheck EXP is still
applicable for G2 (Generation 2).
The product is connected to the computer using short-
range Bluetooth® or a USB service cable.
5.1 Installation and login
Autocheck 3 supports Windows OS 7 and later.
Compatibility with other operating systems cannot be
guaranteed.
5.1.1 Getting log in credentials
The log-in credentials determine the set of capabilities
available within Autocheck 3.
To get Autocheck log-in credentials, either contact your
local sales support, or order Autocheck through the
Dealer Portal (requires access).
Note: Distributors can request access to Autocheck
through the Husqvarna IT service portal. Access to
Husqvarna IT service portal can be ordered through the
Husqvarna sales representative.
5.1.2 Installing Autocheck 3
Autocheck 3 is available for downloading from the
manufacturer's support site.
1. Select AFTER SALES – Autocheck 3 follow link to
SW installation .
2. Download Autocheck 3 according to the instructions
on the Support site.
3. Run the installation file.
5.1.3 Log in to Autocheck 3
1. Start Autocheck.
2. Enter your username and password, refer to Getting
log in credentials on page 9 .
Note: At the first log-in after installation, Autocheck
requires access to internet for user and password
validation.
5.2 Product connections
The product can be connected to Autocheck with both
Bluetooth® and USB service cable. Tests and firmware
updates are available with both connection methods.
USB service cable connection is faster and
recommended to use.
5.3 To connect the product with USB service
cable
1. Remove the service plug.
2. Connect the service cable between your computer
and the product.
3. Start Autocheck on your computer.
4. Set the Main switch to 1 .
5. When the work in Autocheck is complete, disconnect
the cable.
6. Install the service plug and make sure it seals
correctly.
The connection between Autocheck and the product is
usually set up automatically. The product is identified
through the product's identification number.
If the text
Mower status: Not connected is shown in
Autocheck, there is no connection with the product:
• Check that the cable is correctly connected in the
computer and in the product.
• Check that the Main switch is set to 1 .
5.4 To connect to the product with Bluetooth®
1. Start Autocheck on your computer.
2. Set the main switch to 1 to switch the product on.
The product is now pairable through Bluetooth® for 3
minutes.
3. The product automatically appears in the list of
devices found.
4. Press the Connect button for the intended device.
The connection between Autocheck and the product is
established automatically. The connection is confirmed
on the Autocheck Home screen.
If the text Mower status: Not connected is displayed in
Autocheck, contact with the product has not been
established:
1541 - 001 - Autocheck service tool - 9

• Make sure that Bluetooth® is enabled on your tablet/
device.
• Switch the product OFF and ON and try again. Refer
to number 1-4 above.
5.5 How to use Autocheck 3
The program’s main functions are grouped in a number
of menus:
• Home
• Auto test
• Manual test
• Firmware
• Actions
• Log book
• Documents
• Customers
• Help
• Settings
5.5.1 Home
When the product is connected to Autocheck an
overview is presented in the Home menu.
Recommended actions are also shown, for example
recommended firmware updates.
5.5.2 Auto test
Auto test is suitable to use for a fast and overall status of
the product. In the Auto test menu you can select or
deselect tests. All tests run in a sequence after you push
Start Auto test . During the tests there are animations
guiding you what to do.
After the Auto test the results are presented in a list.
When clicking on a test there is more information
presented on the screen. It is also possible to print a
report of the test result.
5.5.3 Manual test
When using the Manual test you select, start and stop
the different tests by yourself. The result is shown live
on the screen and there are no test reports available.
Manual test is appropriate to use when you want to test
a specific component and allow it to work for a certain
period.
5.5.4 Firmware
In the Firmware menu Autocheck updates the product
firmware if necessary.
CAUTION: Always let Autocheck complete a
started programming process. An interrupted
programming can block the motor control circuit
board or the application circuit board.
5.5.5 Actions
The
Actions menu shows:
• Reset : Contains reset functions, for example Reset
charge cycles counter and Reset period time . Reset
charge cycles counter should be done when the
product has a new battery. Reset period time should
be done before the product is returned to the
customer (if there is a need to create a new loop
signal between the product and the charging
station).
• Unit replacement : Has the functionality to set the
product serial number if the application circuit board
is exchanged.
• Advanced mower settings : Contains additional
functions like Demo mode and Override loop
detection . It is also possible to get the Security code
from the product.
5.5.6 Log book
The Log book contains the Fault memory where, for
example, the product's error codes can be found.
5.5.7 Documents
When a product is connected to Autocheck, only the
relevant technical documentation for that model is
shown. It is however possible to uncheck the box for the
connected product and search for all available
documents in Autocheck, for example spare parts lists,
service bulletins, workshop manuals and operator's
manuals.
5.5.8 Customers
In the customer's menu a list of all the customers and
their products is available. The list is only saved locally.
It is possible to import, export and merge customer lists.
This can be used if you have a number of computers in
your organization.
5.5.9 Help
Here you can find more information about how to use
Autocheck. There are also Frequently Asked Questions
(FAQ), instructional videos and release notes.
5.5.10 Settings
Here you can enter dealer information, change
language, set date format and unit format. To apply the
new language or time format Autocheck must to be
restarted.
5.6 Programming a new application circuit
board
If the application circuit board is replaced, the new
application circuit board must be programmed. The
application circuit board includes information about the
product’s serial number.
Note: A new application circuit board may for safety
reasons only be assigned one serial number which is
never changed. It is therefore very important that the
new application board gets the correct serial number.
10 - Autocheck service tool 1541 - 001 -

There are 3 options when programming a new
application circuit board:
•Select product from the Log book
Select product from the Log book and the serial
number and operating data is transferred
automatically to the new application circuit board.
This requires that the product previously has been
connected to Autocheck.
•Enter the serial number manually in Autocheck
If the product never was connected to Autocheck,
the serial number must be entered manually in the
Actions - Unit replacement menu. It is then very
important to enter the correct serial number.
•Use service mode
If the application circuit board is replaced when
troubleshooting, and you are not sure if the
application circuit board will be kept in the product, it
is possible to temporarily skip to enter the serial
number and use the application circuit board in
Service mode. When the product is in Service mode,
the text Service mode flashes in the display. Only
Autocheck can be used to control the product in
Service mode.
WARNING: Do not return the product to the
customer in Service mode.
5.7 Demo mode
Demo mode is used for installations outside shops or
exhibitions. The product alternates between short
periods of operation, docking and charging. Demo mode
can be enabled and disabled in Autocheck.
WARNING: Do not have the blades installed
when the product operates for demonstration in
public areas such as shops and exhibitions.
5.8 To recover the PIN code
If the customer has a registered e-mail address in the
Automower® Connect app, there is a link to get the PIN
code by e-mail. If the customer does not have a
registered e-mail address, the PIN code can be retrieved
via Autocheck and local sales support.
1. In Autocheck, select Actions - Advanced mower
settings - Get security code to upload the security
code to the cloud.
2. Speak to the local sales support and tell them the
serial number. They can identify the correct PIN
code.
1541 - 001 - Autocheck service tool - 11

6 Repair instructions
This chapter describes how to repair and change spare
parts. Refer to the Illustrated parts list (IPL) at the
manufacturer's support website.
6.1 Product overview
6.1.1 The body system
The body system is structured mechanically around the
modules that follow:
Note: The body system is different between the models.
All of the models do not have all of the parts in the list.
1. Body
2. Rear bumper
3. Front top cover
4. Rear top cover
5. Ultrasonic sensors
6. Headlights
7. Front bumper
• 550 EPOS
1
5
2
4
3
6
• 550H EPOS
1
5
7
2
4
3
6
6.1.2 The center console
The center console is structured mechanically around
the modules that follow:
1
2
3
1. Center console
2. Hatch
3. START/STOP button
6.1.3 The upper chassis
The upper chassis is structured mechanically around the
modules that follow:
2
3
1
1. Joystick, rear
2. Joystick, front
3. Upper chassis
Note: There is a sealing strip between the upper and
lower chassis. Always replace the sealing strip when the
product is opened.
12 - Repair instructions 1541 - 001 -

6.1.4 The lower chassis
The lower chassis is structured mechanically around the
modules that follow:
3
2
1
1. Lower chassis
2. Front wheels
3. Rear wheels
Note: There is a sealing strip between the upper and
lower chassis. Always replace the sealing strip when the
product is opened.
6.1.5 The cutting system
The cutting system is structured mechanically around
the modules that follow:
2
13
1. Height adjustment motor
2. Cutting motor
3. Blade disc
6.2 To mount screws
It is important to mount the screws correctly. Incorrect
mounted screws may harm the product. The screw
dimension is Torx 20 when there is no other information.
Note: Read the section about how to mount screws in
plastic before starting any maintenance. Refer to To
mount screws in plastic on page 31 .
Note: Always use the recommended torque to mount the
screws. Refer to Screw fasteners on page 35 .
6.3 To remove and install the body
CAUTION: Pull the connector. Do not pull the
cable.
CAUTION: Clean dirt and grass from the
product before you remove the parts.
1. Set the Main switch to 0 .
2. Clean the area around the grommets.
3. Pull out the rubber grommet and disconnect the
charge cable.
4. Pull out the rubber grommet and disconnect the light
cable.
5. Pull out the rubber grommet and disconnect the
ultrasonic cable.
1541 - 001 - Repair instructions - 13

6. The body is attached to the chassis at 4 positions. At
each position, hold the chassis with one hand and
remove the front cover with a fast and short pull.
7. Install in opposite sequence.
Note: Make sure the that the grommets are correctly
installed to seal against moisture.
6.4 To remove and install the upper chassis
1. Remove the body. Refer to To remove and install
the body on page 13 .
2. Remove the 14 screws.
3. Remove the warranty seal at the point of separation
between the chassis halves on the right side.
4. Lift the front end of the upper chassis.
5. Disconnect the power cables (A) from the motor
control circuit board.
B
C
A
CAUTION: Always disconnect the power
cables first to prevent current spikes that
may harm the circuit boards or the battery.
6. Disconnect the cable (B) and the cable (C) from the
motor control circuit board.
7. Remove the upper chassis.
8. Install in opposite sequence.
14 - Repair instructions 1541 - 001 -

9. When you connect the cables make sure to put the
cables in the cable holders. To put the cables into
position in the upper chassis:
To put the cables into position in the lower chassis:
Note: Attach a new warranty seal. The warranty seal
must be included and unbroken for the warranty to be
valid.
CAUTION: The cable routing is important to
avoid disturbance of the loop sensor board.
CAUTION: Always connect the HMI cable
before the power cable to avoid current spikes
that may harm the circuit boards or the battery.
CAUTION: Make sure that no cables are
pinched.
CAUTION: Replace the sealing strip each time
you install the upper chassis.
6.5 To remove and install the center console
1. Remove the body. Refer to To remove and install
the body on page 13 .
2. Remove the upper chassis. Refer to To remove and
install the upper chassis on page 14 .
3. Disconnect the cable for the center console from the
application circuit board.
4. Pull out the rubber grommet.
5. Disconnect the cable.
6. Remove the 3 screws.
7. Lift up the center console.
8. Install in opposite sequence.
1541 - 001 - Repair instructions - 15

6.6 To replace the top cover
1. Remove the body. Refer to To remove and install
the body on page 13 .
2. Remove the 10 screws that hold the top cover to the
body.
3. Remove the clips from the bottom of the body and
pull the top over out.
4. Use a flat screwdriver to press the 4 clips and pull
up the front top cover.
5. Install the new top cover into the clips.
6. Install in opposite sequence.
6.7 To replace the rear bumper
1. Remove the body. Refer to
To remove and install
the body on page 13 .
2. Remove the 4 screws that hold the rear bumper to
the body.
3. Remove the rear bumper.
4. Install in opposite sequence.
Note: For 550H EPOS the 2 outer screws have a
different tightening torque. Refer to Screw fasteners
on page 35 .
6.8 To replace the front bumper 550H EPOS
1. Remove the body. Refer to To remove and install
the body on page 13 .
2. Remove the 6 screws that hold the front bumper to
the body.
3. Remove the front bumper.
4. Install in opposite sequence.
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6.9 To replace the headlights
1. Remove the body. Refer to To remove and install
the body on page 13 .
2. Remove the top cover. Refer to To replace the top
cover on page 16 .
3. Press the clip underneath the body to release the
headlight.
4. Disconnect the headlight cable from the body.
5. Install the new headlight and connect the cable to
the body.
6. Install the top cover and the body in opposite
sequence.
6.10 To replace the buzzer
1. Remove the body. Refer to To remove and install
the body on page 13 .
2. Remove the upper chassis. Refer to
To remove and
install the upper chassis on page 14 .
3. Remove the 2 screws that holds the buzzer.
4. Disconnect the cables connected to the buzzer from
the application circuit board.
5. Pull out the rubber grommet and remove the buzzer
with the connected cable.
6. Install in opposite sequence.
Note: Make sure that the grommets seal correctly
against moisture.
6.11 To replace the main switch
1. Remove the body. Refer to To remove and install
the body on page 13 .
2. Remove the upper chassis. Refer to To remove and
install the upper chassis on page 14 .
3. Remove the motor control circuit board. Refer to
To
replace the motor control circuit board on page 20 .
4. Press the clips together to remove the main switch
and press it out through the opening in the lower
chassis.
5. Install the new main switch together with the new
gasket into the opening.
Note: Make sure that the main switch is installed
with the digit 1 is positioned to the left and 0 to the
right, seen from behind.
6. Press the main switch into the opening. Make sure
that it is correctly attached and completely sealed.
7. Install in opposite sequence.
6.12 To clean and replace the ventilation filter
Note: The ventilation filter needs to be cleaned regularly
and must be replaced if damaged.
1. Remove the body. Refer to To remove and install
the body on page 13 .
2. Remove the center console. Refer to To remove and
install the center console on page 15 .
3. If the filter is not damaged, clean the filter carefully
with a clean and soft brush and move to step 7.
4. Remove the damaged filter.
1541 - 001 - Repair instructions - 17

5. Clean fully around the mounting surfaces.
6. Attach the new filter. Make sure that the adhesive
surfaces attach correctly to the chassis.
7. Install in opposite sequence.
6.13 To replace the front joysticks
1. Remove the body. Refer to
To remove and install
the body on page 13 .
2. Remove the upper chassis. Refer to To remove and
install the upper chassis on page 14 .
3. Remove the 3 screws that holds the front collision
brackets to the chassis.
4. Remove the 3 screws that holds the bracket to the
joystick.
5. Remove the stud (13 socket wrench).
6. Remove the washer and the bellows.
7. Replace the joystick or bellows.
8. Make sure that the nut is in position in the joystick.
9. Install the bracket.
10. Install the bellows and make sure that the bellows
seal around the retainer.
11. Install the washer and make sure it is in position with
the keys to seal correctly.
12. Install the upper chassis and the body in opposite
sequence.
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6.14 To replace the rear joysticks
1. Remove the body. Refer to To remove and install
the body on page 13 .
2. Remove the 4 screws that hold the rear joysticks to
the upper chassis.
3. Lift up and remove the rear joysticks.
4. Install in opposite sequence.
6.15 To replace the START/STOP button
This section gives information on how to remove all
parts. For service or to replace a spare part, all steps
may not be necessary.
1. Remove the body. Refer to To remove and install
the body on page 13 .
2. Remove the center console. Refer to To remove and
install the center console on page 15 .
3. Open the hatch fully to the START button and pull it
forward.
4. Remove the screw (A) for the LED housing
assembly.
B
A
5. Remove the screw (B) for the START/STOP button
support.
6. The START/STOP button will be released.
7. Install the new START/STOP button.
8. Install in opposite sequence.
Note: Make sure that the spring for the hatch is
positioned correctly.
Note: The cable routing for the LED cable is important.
1541 - 001 - Repair instructions - 19

6.16 The circuit boards and sensors
These are the circuits boards in the product:
7
5
2
8
9
1
6
4
10
11
7
5
3
1. Motor control board (rear loop sensors and tilt
sensor)
2. RTK module
3. Application circuit board
4. Communication circuit board
5. Ultrasonic sensors
6. Front loop circuit board (front loop sensors)
7. Lift sensor circuit board (lift sensors)
8. Front collision circuit board (front collision sensor)
9. Rear collision circuit board (rear collision sensor)
10. Cutting height circuit board (cutting height sensor)
11. Ultrasonic circuit board
The circuit boards contain the electronics and firmware
necessary to control the products functions.
The motor control circuit board, RTK module, ultrasonic
circuit board and the application circuit board and the
communication circuit board contain their own separate
firmware. If any of these boards are replaced, they must
be programmed in Autocheck.
The other circuit boards do not have any firmware, and
do not need to be programmed after a replacement.
CAUTION: Pull the connector and not the cable.
CAUTION: Do not touch the components or pin
terminals on the circuit board.
CAUTION: If the circuit board is to be checked
in order to evaluate the warranty, it must be
placed in a bag with protection against ESD
(electrostatic discharge).
CAUTION: Always protect the product from
electrostatic discharge, ESD, before you start to
work on electrical components.
6.16.1 To replace the motor control circuit board
1. Remove the body. Refer to
To remove and install
the body on page 13 .
2. Remove the upper chassis. Refer to To remove and
install the upper chassis on page 14 .
3. Disconnect the power cables from the motor control
circuit board.
CAUTION: Always disconnect the power
cable first to prevent current spikes that may
harm the circuit boards or the battery.
4. Disconnect all the other cables from the motor
control circuit board.
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