SKODA Self Study Program 17 – The Decentralized Convenience Electronics System in the OCTAVIA SSP-17-Octavia-convenience-electronic-system

The Decentralized Convenience Electronics
System in the SKODA OCTAVIA

CAN BUS

SP17-1

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C

O

HELP

Q

V.A.G.

1552

The SKODA OCTAVIA features a decentralized
convenience electronics system, which comprises the following base functions:

–Electric central locking with superlock and interior light control

–

Electric window lifters with roll-back function

–

Electric mirror adjustment.

The following are also integrated optionally

–

Radio remote control
Anti-theft alarm including interior monitor.

–

These convenience functions are interlinked by a CAN bus system which enables all of the sy­stems to transfer data.

Comprehensive self-diagnosis assists service work.

Important!

SP17-2

Before carrying out any service work on the system, the first action is to start the self-diagnosis.
Model changes may result in modifications to individual functions.
For this reason, always refer to the up-to-date workshop manual.

2

Index

Convenience Electronics 4

The Convenience Electronics System
System Structure in the Vehicle

Functions 8

The Driver's Door as an Example of the Operating
Principle of the Convenience Electronics
Central Locking
The Driver's Door as an Example of the Function Diagram
of Central Locking
Electric Window Lifters
Interior Light Control
Radio Remote Control
Mirror Adjustment, Mirror Heater

10
11

12
14
16
18

4
6

8

Central Control Unit 19

Self-Diagnosis 20

Special Functions 24

Special Functions in the Event of a Crash
Emergency Operation Functions
System Behaviour in the Sleep Model
Opening Versions of Central Locking

Mechatronics 28

Door Lock Electronics
Door Lock with Microswitch
The Rotary Tumbler Switch

CAN BUS Dictionary 31

Test Your Knowledge 32

24
25
26
27

28
29
30

Refer to the Workshop Manual for notes on
inspection and servicing, setting and repair
instructions.

Service Service Service Service

Service

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Service

3

Convenience Electronics

The Convenience Electronics System

E

D

C

B

A

The control units of the convenience electronics system

A = Convenience electronics central control unit J393
B = Driver's door control unit J386
C = Rear left door control unit J388
D = Passenger's door control unit J387

The decentralized convenience electronics system of the OCTAVIA comprises a central control unit
and four door control units.

Each door control unit operates independently (decentralized). The central control unit does not
have any master function.

The control units of the 4 doors and the central control unit are interlinked by a 2-wire dataline
(CAN = Controller Area Network).

E = Rear right door control unit J389

SP17-8

The central control unit is at the same time the access point for the diagnostic interface of the
vehicle.
Diagnostics is conducted using the K wire connection of the central control unit.

Information from the doors (switch signals, locking states) are signalled to the other users along the
CAN datalines.

Information from the vehicle (e.g. ignition terminal 15, rear window heater, vehicle speed) is supp­lied by the central control unit as part of data transfer.

4

Convenience Electronics System

Control Components

Decentralized Centralized

Door control units Central control unit

– Interior light control
– Tailgate central locking

– Central locking and SAFE

state

– Electric window lifters with

roll-back function
– Mirror adjustment
– Mirror heater

D I A G N O S T I C S

– Anti-theft alarm with and

without interior monitor

– Monitoring and swit-

ching off power supply of
interior light and lug­gage compartment light

– Operation of sliding/til-

ting roof

Note:
Vehicles equipped with the convenience electronics system on the one hand are not equi­valent to vehicles fitted only with the central locking system on the other hand.
The highest equipment level is offered by the convenience electronics system with central
locking, electric window lifters and radio remote control.

Models with a lower level of equipment feature central locking with manually operated
windows.

The description of the convenience electronics system in this booklet relates to the high­est equipment level.

5

Convenience Electronics

System Structure in the Vehicle

M

31

31

31

B

2

Z

F

D

4

M

M

M

M

8

8

4

5

C

4

M

8

M

CAN-H
CAN-L

CAN-H

CAN-L

A

M

8

K

Y

CAN-H
CAN-L

M

8

M

M

E

4

M

8

CAN-H
CAN-L

M

M

SP17-09

6

The structure diagram clearly illustrates the benefits of the CAN bus system in the vehicle:
– Greatly simplified wiring.

– Short wiring runs between sensors, actuators and control unit in the door area.

This wiring ( ) is restricted to the door area.

– Only 5 wires have to be run through the separation point of the door to the vehicle. These are

the CAN-H and CAN-L wires, the vehicle earth (31), the power supply for the window lifters
(30F) and central locking (30Z).

– The CAN is linked by 4 connector stations.

These are positioned at the left and right each at the A and B pillars.
Each connector station has its own earth point.

The data transfer which takes place in the normal operating mode is structured in a very simple way.
Each control unit sends a message every 20 ms. This message contains the status data and com­mands.
All the bus users are therefore informed regarding the current operating status of the system at this
interval.
Failure of a system user is detected by a message not being sent.
Event-related data transfer takes place in those circumstances when special operating modes are
activated.
Special operating modes are e.g. in the service sector: recoding, diagnostics, adaptations.

Legend

A = Convenience electronics central control system J393 with aerial
B = Driver's door control unit J386

C = Rear left door control unit J388
D = Passenger's door control unit J387
E = Rear right door control unit J389
K = K wire diagnostic connection

Activation display

Door lock

M

Mirror

M

M

Mirror adjustment switch

Window lifter pushbutton

M

M

Boot lock

Interior light/Luggage
compartment light

Electric sliding roof

M

Window lifter motor

Airbag control unit

7

Functions

The Driver's Door as an Example of the Operating Principle of the
Convenience Electronics

The following components are integrated in
the driver's door:

– Central locking system
– Electric window lifter
– Electrically adjustable exterior mirror

with heater

– Mirror adjustment switch for left and right

exterior mirror

– Switch console for all window lifters,

safety switch (locking switch for opera­ting rear window lifters), central locking
switch

In a system with
the central locking control unit would be

positioned behind the instrument panel.
The window lifter motors and mirror adjust­ment motors in this case are operated
directly by the relevant switches.
Status messages are supplied along sepa­rate wiring through the door contact swit­ches.
Additional wiring is also required for opera­ting the central locking motor.

What this would mean is:

About 33 wires

the driver's door to the interior.

conventional technology

would have to be run from

If door control units using the

system

which have to be run through the door
separation point, is reduced

are used, the

number of wires

to 5

SP17-10

CAN bus

.

8

The driver's door control unit forms a unit together with the switch console (the door control unit in the
other doors is positioned at the window lifter motor.

Functions

Controlling the central locking

– Detecting whether door is closed/

open

– Detecting key position

(lock/unlock)

– Controlling the central locking

motor in the door lock

Controlling the window lifter

– Detecting operation of pushbutton

(with selection of which window is
opened)

– Operating the motor in the

driver's door

– Detecting the need to activate the

roll-back function

Controlling mirror adjustment and hea­ter

– Detecting operation of adjustment

switch and mirror selection

– Operating the motors and, as

appropriate, the heater

Transmitting information through the
CAN bus to other doors

– Window lifters
– Closing central locking
– Right-hand exterior mirror
– Forwarding electric fault messa-

ges on request

Receiving information from the central
control unit

SP17-11

Note:
Entire keypad of the switch console is de­activated if the car has been locked from
the outside.

– Lock/unlock central locking

system (with radio remote con­trol)

9

Functions

Central Locking

Locking zones

All doors, tailgate

Exterior operating points

Driver's door lock cylinder
Front passenger's door lock cylinder
Tailgate lock cylinder

Optionally remote control

Interior operating points

Lock/Unlock button in driver's door

Special features

When the doors are locked, they move into
the theft-protected status (= SAFE).
This is indicated visually by an LED next to
the interior locking button in the driver's
door flashing.
In the SAFE status, the interior locking but­ton is disconnected mechanically, the door
can only be opened from the inside using
the door handle.
All 4 doors are locked simultaneously with
the Lock/Unlock button.

If the interior locking button is operated,
only the door of the relevant operating point
is locked.

Lock/Unlock
button driver's
door

SKODA

SP17-4

SP17-7

10

Initial situation Safety status

A CLOSE command from
outside and ignition off

Two CLOSE commands from All doors locked
outside within 5 seconds and from Luggage compartment locked
same operating point

An OPEN command from
an operating point

Note:
CLOSE commands are only carried out if the door of the operating point and
the driver's door are closed.
Refer also to page 30.

All doors SAFE, SAFE LED comes on

Vehicle is unlocked completely
Luggage compartment unlocked if lock position “I”
Luggage compartment locked if lock position “–”

Driver's Door as an Example of Function Diagram of Central Locking
System

The central locking system operates on the electromotive principle.
Each door has a locking unit (F220 to F223) and a door control unit (J386 to J389).
The tailgate has an actuator F217.

The locking operation includes:

– Operation of all the users at the lock

system,
– The "lock" function in the door locks,
– The information for initiating other

convenience functions to the central
control unit (e.g. locking tailgate,
operating interior light, operating
anti-theft alarm).

F221

F223

Example of the sequence of a locking
operation (block diagram)

– The driver's door control unit J386 is

activated by the locking unit F220 as

a result of the locking operation using

the key.
– A data transfer check is carried out in

J386 to determine whether locking
can proceed, e.g. "is driver's door
closed?"

– Information to own locking unit F220

"Lock driver's door".

– Signal over dataline (CAN) to central

control unit J393 and to all door con­trol units for locking operation.

– All door control units independently

initiate the "lock" function.

J393

J387

J386

F220

SKODA

J389

F217

J388

F222

SP17-6

– At the same time, the windows are

closed and the locking buttons of the
doors automatically blocked (SAFE
status).

– The convenience electronics central

control unit J393 activates the tail­gate actuator F217, switches off the
interior light and activates the anti­theft alarm.

The procedure can also be initiated using the radio
remote control depending on the vehicle equipment
(refer to page 16).

11

Functions

Electric Window Lifters

The OCTAVIA features power-operated
window lifters at the front and rear side win­dows as optional equipment.

Each door is provided with a window lifter
motor.

The window lifter motor operates a cable
system to which the window is attached.

The window lifter motors are controlled
decentralized through the relevant door
control unit.

The window lifter drive features an electro­nic power limiter (roll-back function).
A Hall sensor in each door monitors the
operating speed of the window lifter motor.

If an obstacle slows down the movement of
the window as it is closing - the speed is
reduced as a result - this is detected imme­diately and the direction of operation of the
motor is reversed.

This reliably prevents any parts of the body
being jammed in the window.

The roll-back function is active if the window
lifters are operated from the inside.
It is not active if the car is locked with the
key.

Door control unit

SP17-31

Cable system

Window lifter
motor

12

SP17-32

Note:
The window lifters have to be initialised each time the battery is disconnected
(determining position of windows).

Interior operating points

– Pull-push button in driver's door for each

window

– Pushbutton in the other doors for the rele-

vant door window

– Child safety lock in the driver's door

Exterior operating points

– Lock cylinders in driver's door, front pas-

senger's door, tailgate

Note:
The window lifter buttons of the rear
windows can be deactivated with the
child safety lock.

Window operation with ignition ON

Pull-push button for driver's door
window lifter

Child safety lock

SP17-5

Automatic window opening

Manually controlled window opening

Automatic window closing
(front windows only)

Manually controlled window closing
(front and rear windows)

Interrupting automatic window operation

Interrupting manually controlled window
operation

Window operation with ignition OFF

No automatic window operations

Function retained

Retention of function interrupted

Press pushbutton briefly (less than 300 ms)

Press pushbutton and hold; window continues to open
so long as pushbutton is pressed (more than 300 ms)

Briefly press pushbutton (less than 300 ms)

Press pushbutton (more than 300 ms) and hold; window
closes for as long as pushbutton pressed

Press pushbutton for this window

Operate second pushbutton for the relevant window
(in the case of windows which can be operated with
2 pushbuttons)

Up to 10 minutes after ignition off

If a front door is opened

Closing

Opening

– Pushbutton: raise until window is closed. No automatic

operation

– Lock cylinder

"Central locking CLOSED" command for more than 1 sec.

– Pushbutton: press and hold briefly. Window opens fully

(automatic opening)

– Lock cylinder

"Central locking OPEN" command for more than 2 sec.

13

Functions

Interior Light Control

The convenience electronics central control
unit J393 performs the controlled (and dim­med) switching on and off of the interior
lights as well as limiting their operating
period.
The operating period of the interior lights is
limited to a maximum of 10 minutes if the
doors are open and the ignition switched
off.

SP17-30

Initial situation

Interior light set to door contact

Status Interior light

Car unlocked with key or remote control

One door is opened from inside
(all other doors closed)

Ignition key is withdrawn when doors clo­sed

–Car is locked with door closed
–Last door is closed with car locked

Switched on until ignition on and doors
closed, dimmed off
(on for max. 30 seconds)

Switched on. Dimmed off 30 seconds
after door is closed

Remains on for 30 seconds, dimmed off

Undimmed "OFF"

Crash sensor activated

14

Undimmed "ON" for 10 minutes

The power for the interior lights and reading light and also for the luggage compartment light is
supplied through the central control unit.

If one or several lights have been switched
on manually, the power is switched off after
1 hour through an internal relay in the cen­tral control unit if the ignition is off.

Protection against battery being dischar­ged!

The procedure is repeated after the rele­vant light has once again been switched
off and on.

30

W

J393

W13

Note:
If several lights have been switched on, all the lights should then be swit­ched off.

This also applies to the luggage compartment light and reading light.

W3

SP17-12

W Front interior light
W3 Luggage compartment light
W13 Front passenger's reading light

15

Functions

Radio Remote Control

The radio remote control can be used to activate the lok­king and unlocking operations of the central locking
system without operating the door lock mechanically.

The radio transmitter with batteries is housed in the
handle of the car key (ignition key).
The radio receiver is integrated in the convenience elec­tronics central control unit.

Indicator light

Locking zones

All doors, tailgate

Operating points

Pushbuttons in ignition key
The ignition key features 2 pushbuttons which have to be

pressed accordingly:
"Central locking OPEN" = Press key 1 briefly once

"Central locking CLOSED" = Press key 2 briefly once

Special features/Operating range

– The radio remote control can be used to

operate the central locking and anti-theft
alarm from a distance of up to 10 metres.
The range is reduced if the capacity of the
batteries in the ignition key weakens.

1

2

SP17-17

– If no door or the tailgate has been opened

within 30 seconds after transmitting an
unlock command with the remote control,
the previous status of the central locking
and anti-theft alarm is automatically recrea­ted.

– An indicator light in the key flashes for as

long as the opening or closing button is
pressed.

16

ca

.

1

0

m

SP17-18

Function

When one of the buttons in the ignition key is pres­sed, a coded signal is transmitted to the convenience
electronics central control unit J393.

The aerial at the central control unit receives the
signal, the control unit analyses it and passes the
control pulse for locking/unlocking the 4 doors and
the tailgate through the CAN to the door control units
and directly to the central locking actuator of the tail­gate.

Transmitter
Power for the transmitter is supplied by 2 batteries.
The radio frequencies are matched to the relevant
national frequencies.

Coding

Transmitter and receiver are coded.
Coding ensures that the vehicle can be opened only
with the key which is supplied with the vehicle.

It is necessary to adapt a radio transmitter key if:

– the system is commissioned (manufacturer)
– an additional key is added
– a transmitter key is operated more than 200 times outside of the reception

range of the vehicle (e.g. playing with the buttons).

Y

J393

F221

J387

J386

F220

F223

J389

F217

J388

F222

SP17-19

Possibilities of initialising:

Version 1

Switch on ignition (with additional key)
Lock car manually with key to be programmed (learned
Transmit a radio signal
Interval > 1 second
Transmit a second radio signal (completion of learning process).

Version 2

Switch on ignition and connect V.A.G tester
Enter system with "46"
Select "10" Adaptation
Cancel all keys, select "00" or initialising mode "01"
Enter number of keys
Readout "Store adaptation?" + enter "Q"
Operate a pushbutton of transmitter key within 15 seconds.

17

Functions

Mirror Adjustment, Mirror Heater

Operating points

– Left mirror selector switch

– Right mirror selector switch

– Mirror adjustment 4-direction rocker switch

Left mirror selector
switch

Mirror adjustment

Requirement operates
Ignition on for as long as

Right mirror selector
switch

4-direction rocker
switch is operated

L

R

SP17-14

4-direction rocker
switch

18

Mirror heater

Requirement operates
Ignition on with rear window

heater on

Central Control Unit

The Convenience Electronics Central Control Unit J393

The central control unit does not perform any
central function (master function) for the con­venience electronics system, but represents
the interface of the 4 control units to the rest of
the vehicle and to the diagnostic connection.

It is positioned in the interior of the vehicle
behind the dash panel insert.

The central control unit combines the
functions which flow centrally into the conveni­ence system of the vehicle, but which it would
technically not be reasonable to integrate in
the decentralized door control units.

– Interior light control

– Tailgate central locking
– Anti-theft alarm with and without

interior monitor

– Receivers for radio remote control

SP17-1

Central functions

– Monitoring and switching off power

supply for interior lights and luggage

compartment light
– Operating sliding/tilting roof
– Diagnostics

(fault memory and access to diagno-

stic connection)

If a central control unit is replaced, it is only necessary to adapt it to the vehicle if a radio remote con­trol is integrated in the system.

The vehicle equipment of central locking with manual window lifters features a different control unit.
The installation point and housing are identical although the contacts differ.
The other functions are identical with the exception of electric window lifters and mirror adjustment.

19

Self-Diagnosis

Diagnostic function of door control units

– Monitoring the functions carried out

in the relevant door
– Storing faults detected
– If a door control unit detects a total

bus failure, it disconnects from the

bus for a limited period and then

once again attempts to transmit a

message.

Electrically adjustable mirror with mirror
heater and mirror adjustment switch

Driver's door control unit J386 with
window lifter buttons, locking switch for
central locking (Lock/Unlock button) and
child safety lock for rear window lifter
buttons

Interior light

L

R

Driver's door window lifter motor

Driver's door lock

Driver's door anti-theft alarm LED

Rear left power window button

Rear left door control unit J388 with
window lifter motor

Diagnostic connector T16

Rear left door lock

20

Electric sliding / tilting roof

Diagnostic function of central control
unit

– Monitoring the functions carried out by

the central control unit

– Storing information regarding faults

which occur

– Interface to diagnostic connector T16

Convenience electronics
central control unit J393

Front passenger's door electrically
adjustable mirror with mirror heater and
front passenger's door window lifter
pushbutton

Driver's door control unit J387 with
window lifter motor

Driver's door lock

Tailgate lock

Rear right window lifter button

Rear right door control unit J389 with
window lifter motor

Rear right door lock

SP17-13

21

Self-Diagnosis

The comprehensive self-diagnosis of the conve­nience electronics can be conducted with the
vehicle system tester V.A.G 1552 or with the fault
reader V.A.G 1551.

Address word: "46 Zentral SG Komfort" (46
Central Convenience CU").

Available functions:

– Interrogating control unit version 01
– Interrogating fault memory 02
– Final control diagnosis 03
– Erasing fault memory 05
– Ending output 06
– Coding control unit 07
– Reading measured value block 08
– Adaptation 10

1

2

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7

8

9

C

O

HELP

Q

V.A.G.

1552

Please refer to the current workshop manual of
the SKODA OCTAVIA for the individual fault
codes.

Note:
The convenience electronics system is characterized by four operating states, which
also appear in the measured value blocks:
– SAFE
– Locked

– Unlocked
– Door OPEN
When carrying out fault finding, the first action is to start diagnosis.
Do not carry out any mechanical work until after completing diagnosis.

Switch on the ignition, enter the address word "46" to create the link to the system and
then you can continue diagnosis with the ignition switched on or off.

All the systems which interchange signals and commands, should be regarded in the
self-diagnosis and in fault finding as a total system.
After carrying out repairs, read the fault memories of all the control units in order to
detect any faults which may be stored.
This principle applies both to the conventional wiring system as well as to the CAN ­Controller Area Network.

SP17-29

Self-diagnosis of the CAN The self-diagnosis for the wiring of the CAN detects

short circuits or open circuits on a CAN wire.

22

Short circuits in the CAN Short circuits are detected for both CAN wires.

This also applies to a short circuit from the CAN-high wire to
the CAN-low wire. If a short circuit occurs at one of these
wires, the relevant wire is then inoperative.

Possible types of faults are:
Short circuit to positive
Short circuit to earth, and
Short circuit to each other.

Self-diagnosis is not able to detect in which part of the CAN
wire a short circuit exists.
The location of the short circuit can only be pinpointed by
disconnecting one after the other the door wiring looms at
the connector station in the A or B pillar and checking the
readout of the measured value block (function 08, display
group 12).

Open circuits in the CAN An open circuit in each control unit can be detected

by comparing the two CAN wires. The fault status is
analysed and signalled to the other control units.
The central control unit gathers these fault messages and
displays or stores them, respectively.

03 Final control diagnosis

The following actuators are displayed in the final control diagnosis function:

Readout in tester Reaction

– Alarm horn -H12 – Alarm horn supplies continuous signal
– Operation of turn signal lights – Turn signal lights come on and remain on
– Interior lights -W – Interior and reading lights come on
– Sliding roof close signal – Sliding roof closes
– Lighting of switches and instruments – Instrument lighting becomes brighter
– CL SAFE indicator light – Comes on

If self-diagnosis signals to the central control unit that a user
is not attainable, the following information is output, e.g.:

Driver's door control unit J386 no communication

Note:
The ignition key has to be withdrawn for
the "Sliding roof close signal" activity.

23

Special Functions

Special Functions in the Event of a Crash

Locked doors represent an additional obstacle for occupants
and rescuers in the event of a crash.

"See and be seen in an emergency situation" is an important
help for other road users.

The electronic convenience system of the OCTAVIA features
automatic circuits which help to minimise the emergency situa­tion in the event of a crash.

Operating requirements

– Ignition on
– Interior light in "door contact" switch position

Activities in the event of a crash

– The central locking is unlocked.
– The interior light is switched on for 10 minutes.

Function

The crash sensor in the airbag control unit J234 is activated
by the deceleration of the vehicle in the event of a crash.

The convenience electronics central control unit J393 receives
the sensor signal.
The actuators for the central locking and interior light are
operated.

F220

F222

J234

J393

F221

F223

SP17-3

24

F220-223 = Locking units

= Interior light

J234 = Airbag control unit
J393 = Convenience electronics

central control unit

Note:
You should advise the customer to set the interior light to the
"door contact" switch position when driving to enable the interi­or light circuit to operate properly in an emergency situation.

These special functions are activated when carrying out final
control diagnosis of the airbag. After this, operation of the cen­tral locking system is not active again until after the ignition has
been switched off and on.

Emergency Operating Functions

As a result of the decentralized design and operating principle of the convenience electronics
system, the effects of any partial defects are kept within very confined limits. For example, failure of
a component in the front passenger's door has only minor effects on the functions in the other
doors.

Special emergency operating functions are a feature of the system safety:

– Two voltage supplies

Each unit features two voltage supplies.
The circuits for the central locking and window
lifters are separate. If one circuit fails, the major
part of the functions is retained.

– 2-wire bus line

The control units are linked by a 2-wire dataline
(CAN-HIGH, CAN-LOW).
If one line fails, the system switches over auto­matically to 1-wire operation. All the functions
are retained. The fault is stored in the fault
memory.

– Signals from faulty sensors

Static signals supplied by faulty sensors/switches do not result in the function being blocked.
Such signals are ignored in accordance with a defined strategy and only those part functions of
the system which are required for safety reasons, are activated.

J386

30A Window lifter

31

30A Central locking

3

CAN-HIGH

23

CAN-LOW

16

31 Earth

32

SP17-28

Examples of emergency operating functions

– Door control unit

The system is protected by setting to SAFE

No data transfer

– Window lifter motor

No further automatic operations

Note:
In order to detect whether bus data transfer still exists, press the Lock/Unlock button
and observe whether the locking buttons of all the 4 doors open and close.
After this, open a door and observe whether the interior light comes on.
If this is not the case, there is an interruption in data transfer to one of the users.

25

Special Functions

System Behaviour in Sleep Status

The convenience electronics system is also operational when the ignition is switched off and the
vehicle is closed (locked).
For this reason, particular significance is attached to the closed circuit current consumption.

Minimal functions when vehicle locked:

– Anti-theft alarm

– LED status display

– Radio remote control

No communication takes place within the network in this sleep mode.
The closed circuit current consumption (without SAFE LED) in the system is about 7 mA.

Signals, e.g. door OPEN

Sleep

Alarm
Remote Control
Status LED

7 mA

Active

150 mA

Wait

Lock command

Ignition off

150 mA

Operating states and relevant closed circuit currents of system

All the events which necessitate a reaction of the entire system (e.g. door OPEN signal), activate an
open circuit in one of the control units and result in a wake-up command in the network.
The system is now in the Active status with a closed circuit current consumption of 150 mA. The
response time until full operational readiness of all control units is less than 100 ms.

SP17-21

If the ignition is switched off all the control units move into the Wait status.
Full system function is retained in this operating state, each control unit still processes any pending
tasks (e.g. window lifter function is retained for a certain time). After all the tasks have been proces­sed or the superlock command received, each control unit sets the set sleep bit in its cyclical mes­sage.

As soon as all the bus users have set this bit and have recognized the set sleep bits of the other
users, they cease data transfer and, after a short waiting time, move into the sleep mode.

26

Opening Version of Central Locking
Coding with V.A.G 1551 / 1552

The convenience electronics central control
unit J393 is programmed (coded) by the
vehicle manufacturer to match the vehicle
equipment and the national version.

It is coded for 4 window lifters and "all
doors" unlocking of the central locking
system.

An existing or a new convenience electronics central control unit can be reprogrammed in
the SKODA Service Centre to "single door opening".

If single door opening is programmed,
only the driver's door is unlocked with an
"OPEN" central locking command using the
key or the remote control. The other doors
and the tailgate are switched from "SAFE"
to locked.

SP17-15

To unlock all the doors, it is then necessary
to supply a second "OPEN" command with
the key or the remote control within 5

seconds.
If need be, the front passenger's door/tail­gate operating point can be unlocked in
dividually with the key.
The car is automatically locked when the
front passenger's door/tailgate is closed.

Please refer to the current workshop
manual of the SKODA OCTAVIA for the
procedure for reprogramming.

Note:
The customer's attention can be drawn to this opening version when purchasing
the car or during the SERVICE Inspection.

Please explain to the customer the new opening version.

SP17-16

27

Mechatronics

Door Lock Electronics

The door contact switches in the driver's and front passenger's doors for the interior light control are
familiar from the SKODA FELICIA.
The interior light is controlled directly and with separate wiring through these door contact switches.
The signal for the central locking is supplied by the microswitch from the central locking actuator to
the central locking control unit, likewise using separate wiring.

Microswitch for
"SAFE" feedback signal
"LOCKED" feedback signal

In the OCTAVIA Convenience System
the relevant signals are sent over the
databus system as information to those
points where it is needed.

The system interlinking is very consi­derably characterized by the interaction
of mechanicals and electronics.

For the first time, microswitches and
electrical connections are integrated
directly in the door locks.

The microswitches signal the following
– "DOOR OPEN" signal

– "LOCK" signal
– "UNLOCK" signal
– "LOCKED" feedback signal
– "SAFE" feedback signal.

They supply within a very confined space
the signals which are necessary for
the process of information in
the convenience system,
without themselves operating directly.

Microswitch for
"LOCK" signal
"UNLOCK" signal

Actuator

Printed circuit
board

Connector to
control unit

Connection to rotary
tumbler switch

SP17-26

Printed circuit board with actuator in door lock

The microswitches and electrical connections are accom­modated on a printed circuit board and take up minimum
space.
Only the rotary tumbler switch, which for operating rea­sons has to be positioned locally at a separate point, is lin­ked by wiring.

28

Door Lock with Microswitch

"LOCK" signal
"UNLOCK" signal

A lock cam is located in the door lock of the
driver's and front passenger doors, and next
to this 2 microswitches.
The lock cylinder projects from the outside
into the lock cam and, on the inside in the
lock, it is provided with cam tracks.

Depending on the locking operation with the
car key - CLOSE or OPEN - the cam tracks
move up against a microswitch.

The microswitch is closed as a result.
Its signal is the commencement of the locking

operation "central locking" with all the subse­quent functions of the convenience electronic
system, e.g. holding lock position in order to
close open windows.

Lock cam

Microswitch

SP17-24

Note:
Manual locking/unlocking of the door lock is also performed by means of the lock cam
in the event that the central locking system does not operate or if the car battery is not
connected.

"LOCKED" feedback signal

The "locked" feedback signal indicates the
lock status to the door control unit. It is provi­ded through a microswitch in the door lock of
each door if the car is locked manually or
electrically.

The central locking module is in the lowest
position in the "unlocked" setting. Its leading
edge presses the microswitch closed.
If the car is locked, it moves up, the micro­switch opens and supplies its "locked" signal.

Microswitch

Central locking
module

This signal is important in terms of the control
unit in order to avoid an electrical actuation
being again carried out. Otherwise the system
would switch to the SAFE position.

Drive gear

SP17-25

29

Mechatronics

The Rotary Tumbler Switch

The rotary tumbler switch is positioned directly below the rotary tumbler in the door lock. It is
located in the lock of each door.
It is operated by the rotary tumbler, which is designed as a cam track.

Its signal is analysed in the door control unit and in
the convenience electronics central control unit J393.

Its purpose is to

– check whether the SAFE status has to be set
– control the interior light.

"Door OPEN" signal

If the "door OPEN" signal is supplied, the cam track of
the rotary tumbler is touching the switch. The switch
is closed.

Note:
The entire central locking system
is not active until the "door OPEN"

signal no longer exists, i.e. the rotary
tumbler switch is again open.
This is the case if driver's door
and operating point are closed.
(Does not apply to driver's door and
locking point if locking point is opera­ted).

Door lock

Rotary tumbler

Rotary tumbler switch

SP17-23

Rotary tumbler switch "door OPEN" position

The tailgate lock also has a rotary tumbler switch at
the rotary tumbler.
It supplies the "tailgate open" message and controls
the luggage compartment light.

30

SP17-22

Rotary tumbler switch "door CLOSED" position

CAN BUS Dictionary

A description of the SKODA OCTAVIA convenience electronics system very often involves the use
of new technical expressions. A number of these are explained briefly below.

Active – Active state of convenience electronics system.
BUS – Bit serial universal interface
Bus system – The individual elements of the convenience electro-

nics system. Databus

CAN – Controller Area Network,

A serial bus system designed specifically for use in
vehicles.

CAN BUS – Several equal access control units are interlinked by

a linear bus structure.
Advantage:

Even if one user fails, the bus structure con­tinues to remain fully available for all the
others.

Decentralized convenience
electronics system – Four decentralized door control units - one in each

Dimming – A method for switching off the lights in which they

Lock/Unlock button – Lock/Unlock button in driver's door for all 4 doors

Mechatronics – Three-dimensional and functional integration of

SAFE – Anti-theft status of door locks in which the vehicle

door - and a central control unit in the dash panel
area are interlinked by CAN data wires.
The central control unit does not have any master
function; each door control unit operates indepen­dently or as a multimaster system (see also CAN
BUS).

become gradually darker until they go out.

and for the tailgate.

mechanicals and electronics.

doors cannot be unlocked manually from the inside
of the door handle.
"SAFE" can only be overridden with the car key
from the outside or by switching on the ignition.

Serial – Arranged one after the other in series.
Sleep – Off state
Wait – Wait state

31

?

Test Your Knowledge

Which answers are correct?
Sometimes only one.
Perhaps in some cases more than one - or all!

....................... means you should complete the blanks

1. What are the advantages which the CAN bus system offers?

?

A. Several equal-access control units can be used.
B. It is possible to significantly reduce individual wiring.
C. It is no longer necessary to have a direct link of the actuators to the power source.

2. A special feature of the central locking system

is locking of the car in the ....................................

state.

........... state is displayed visually.

3. The entire central locking system is not active until the

....................message no longer exists.

This message comes from the .....................................

4. The car can be equipped optionally with
A. a radio remote control

B. an infrared remote control
for the central locking.

The maximum distance for using the remote control is ...... m.

5. Information regarding the door status e.g. door

32

"OPEN" or door "CLOSED" or commands pass
A. from the microswitches to the door control unit

B. to the convenience electronics central control unit
C. to the other system users

1. A; B 2. The theft-protected; SAFE 3. Door "OPEN", rotary tumbler switch 4. A; 10 5. A; B; C.
Answers:

?

31
30 F
30 Z

Y

K

SP17-27

6. Supplement the CAN network and provide the designations of the 5 control units.

7. The SKODA OCTAVIA convenience electronics system comprises a special "emergency situation"
circuit in the event of a crash.

In a crash, the .................. is unlocked and the interior light switched on for ....... minutes.

The operating requirements for this are ........................ on and interior light ......................

8. Comprehensive self-diagnosis is possible by selecting the address word "46 Zentral-SG Komfort"
(46 Central Convenience CU).

A. The system link can be established irrespective of the ignition being on or off.
B. The system link can only be established when the ignition is switched on.
C. Diagnostics relates only to the central locking system.

9. Each door lock and the tailgate lock feature a rotary tumbler switch.
The rotary tumbler switch is a microswitch; it is integrated into the

system in place of the .......................................

10. The 4 door control units are a feature of the decentralized convenience electronics system.
They operate

A. the central locking
B. the SAFE status as soon as the ignition is switched on
C. the electric window lifters

6. Graphics page 6 7. Central locking; 10; Contact, Ignition; door contact 8. B 9. Door contact switch 10. A; C.
Answers:

33