Retrofitting COMAND to Mercedes Benz Vehicles
28th March 2003 - Version 1.10
This document describes how to retrofit COMAND to certain Mercedes Benz
vehicles, and how to fit COMAND to non Mercedes vehicles.
It is the summary of information that I know (from playing with COMAND
systems for a while), and information gained from the mbworld.org discussion
I don't warrant that any of this is correct, and if you damage your car then
that is your responsibility. If you have Teleaid/E-Call, be careful to check
that all works once you have finished. Do this at your own risk. If you do
connect things wrongly you could considerably (and expensively) damage your
car. If you are in the US and want Teleaid to work, you must use US COMAND
unit not a European one.
Retrofitting COMAND to Mercedes Benz vehicles (where COMAND was available
but was not ordered from the factory) is not that difficult. It is made
considerably easier if the aerial cabling for the GPS aerial is already
present (which it is in the M class and for all US vehicles, although some
extension cables or a splitter may be needed on some vehicles), or if you
are willing to install a separate GPS aerial rather than the "factory
fitted" version on the roof/rear-window of the vehicle.
There are three types of COMAND: -
Comand 2.0 - the unit without a cassette deck (that is 2 din units in
size) - this comes with either the square front (old CLK/E class, ML class)
or the curvy front (C/CLK/SL/G-Wagen)
Comand 2.5 - the unit with a cassette deck used in S and CL, it is 2.5 din
units in size.
Comand 16x9 - this is a Comand 2.0 unit with a 16x9 display and is currently
installed in the S/CL class from model-year 2003.
This document really only deals with installing Comand 2.0 units.
2) Purchasing a COMAND unit
The cheapest place to purchase a COMAND unit is from Ebay - search for items
available to Germany - most German sellers list locally, but will ship
internationally if you pay. Be aware that it is normal for buyers to pay the
EBAY selling fees.
There have been a number of cases of non-functioning units bought from ebay,
or different part numbers supplied - so beware.
You can obtain used units from: -
Steve MBenzNL [s firstname.lastname@example.org] http://www.mbenz.nl /
Megacomm http://www.megacomm.de /
Audiocomp http://www.audiocomp.info /
If you have a relatively new car, you should buy the latest available unit
for your model. Mercedes part numbers take the format: -
A XXX YYY ZZ BB
The XXX is the vehicle model number that the part first appeared in, here is
Current C class
You should purchase the part starting with the correct code for your car
otherwise the catch mechanism will be wrong, the gyroscope angle will be
wrong, and at a minimum it won't work until a MB dealer has re-coded it.
Be ware that if you have one of the earliest CLK or E (ie model year 1999
and before) then you need to purchase the exact unit that would have been in
the car, or a M class unit - consult your MB parts department for the part
number. The older cars do not have CAN bus connected to the radio/command
(and nor does the M class).
Also, if you are installing in a ML (or a car not designed for Comand) you
must by a ML unit - although some W208 CLK units can be made to function.
I believe that the new CLK/C/SL/G-Wagen units may be interchangeable, but
they will only fit in Mercedes Benz vehicles as they have non DIN shaped
Here is an incomplete list of COMAND unit part numbers: -
163 820 14 89
163 820 36 89
203 820 91 89
203 820 96 89
203 827 36 42
Up to 9/2002
203 827 52 42
203 820 92 89
203 827 31 42
203 827 37 42
203 827 53 42
203 827 23 42
C (new), G-Wagen
203 827 54 42
208 820 30 89
208 820 31 89
208 820 37 89
208 820 38 89
208 820 34 89
208 820 35 89
208 820 40 89
208 820 44 89
210 820 48 89
210 820 51 89
210 820 54 89
210 820 56 89
220 820 03 89
220 820 04 89
220 820 46 89
220 820 47 89
220 820 71 26
220 820 72 26
220 820 34 89
220 820 35 89
220 820 48 89
220 820 37 89
220 820 40 89
220 827 04 42
220 820 58 89
220 820 59 89
220 820 60 89
230 820 05 89
230 820 25 89
230 820 23 89
Up to 31/10/02
230 820 29 89
230 820 06 89
463 820 10 89
463 820 15 89
If you use a European COMAND unit on a US vehicle then weatherband will not
work and AM radio reception will be incomplete because Europe uses a
different spacing between stations than USA. European COMAND units have a TV
button. US units have a blank button instead. The latest US units can be
made to work with TV, older ones can't. Early COMAND 2.5 units do not
support TV. US units do not support RDS text, European units do.
I suspect that having a US dealer install the latest US software on a
European COMAND unit will make weatherband work again, but lose RDS text.
The COMAND unit has an inbuilt gyroscope, which must be aware of the angle
that the unit is mounted in the dash. On the side of the unit is a special
clip - different coloured clips are used for the different angles - if the
wrong one is installed, navigation may not work well. These are the clips I
am aware off: -
E Class (W210)
CLK Class (W208)
3) Head Unit Connectors
The standard Mercedes head-unit's have various connectors: -
A Power connector
B Speaker connector
C Mercedes-benz special connector (CD power, CANbus
D2B D2B fibre optic connector
D Antenna connector
F Diverse Antenna connection (on Audio-30 for
COMAND has the following connectors: -
A Power connector
B Speaker connector
D2B D2B fibre optic connector
D Main Antenna connector
F Diverse Antenna connection (small coax connector)
E GPS antenna connector (square grey coax HRS
C1 Mercedes Benz 18-way high density connector
C2 Mercedes Benz 8-way high density connector (TV
RGB, CD power)
Note, if you car has the Digital BOSE system, connector B will be empty as
the amp connects to the head unit via the D2B fibre optic connection.
4) GPS Antenna
4.1) ML MY2002 onward
On all M Class vehicles there is a combined roof antenna for GPS, Telephone
and Teleaid systems. If its not installed you will have to purchase and
There are separate coax cables already installed from the aerial to the back
of the head unit (GPS), and from the aerial to under the right-hand seat
To installing the antenna: - Open the rear door, and pull off the top-centre
trim panel, start at left side, and pull down gently to release the first
clip and work along. You can then access where the underside of where the
antenna fits to install it.
4.2) ML MY2001 and before
On older vehicles there is only one COAX lead from the antenna to the back
of the head unit and a splitter is needed at the head unit end.
Part Numbers: -
ML 2002 Combined Antenna A163
820 15 75
Pre MY2002 Combined Antenna A163 820 18
Pre MY2002 GPS Splitter A163 820 30 89
Pre MY2002 Cable from splitter to COMAND A163 540 09 13
4.3) C (W203) and CLK (W209)
The antenna is at the top of the rear windscreen. On US vehicles the aerial
wiring is all in place and the connection for COMAND is already behind the
radio (along with the diverse FM antenna for command (small coax connector).
The GPS aerial is stuck to the rear windscreen at the top in the middle.
The following parts are needed (note that the GPS aerial and aerial lead is
probably in place on US vehicles): -
TBA - ask dealer
GPS lead from aerial to front of car
A203 540 70 06
4.4) CLK (W208)
The aerial is on the roof, at the rear. The GPS aerial cable should run
along the roof lining parallel to the rear windscreen on the right of the
car. (The phone aerial runs along to the left of the car). It then runs down
beside the windscreen, and along the panel to the right of the rear
passenger and in the wiring duct below the right hand door sill, across the
front of the right hand seat and up into the centre console, and then to the
If your car has Teleaid, then the cable will run to the Teleaid unit (in the
middle of the boot/trunk, under the black plastic panel under the carpet).
You could install the proper GPS aerial combiner, which is part number A210
820 24 89 (if its not there already) and run the aerial cable from there to
COMAND. If the splitter is there, then the aerial cable running to the front
of the car is probably already installed.
Note, that it may be easiest to run the cable above the foot-well and into
the back of the COMAND, rather than across the front of the right hand
seat - that saves some dismantling of the centre console.
4.5) Other Cars (or I don't have a GPS aerial already installed)
Mercedes sell a GPS antenna that can be stuck to the underside of the
dashboard (looking up through the windscreen) with the appropriate plug to
connect to the COMAND unit. This is part A230 820 08 75 and is around
£40+VAT or E50 + tax. It is normally used on the SL where it is fitted to
the top middle of the windscreen.
Be aware that vehicles have windscreens with a metallic coating that will
prevent GPS signals passing through them.
5) Making up the converter loom.
Rather than modifying the car's loom, it is better to make (or purchase and
modify) a wiring loom converter harness.
An adapter loom is available from Mercedes
This does the same as the loom described in the "other vehicles" section
below, but (a) it has a 20cm GPS aerial cable that connects to the pre-wired
connector and to COMAND, (b) it doesn't have CAN and (c) connects the
reversing signal to the COMAND.
MY2002 Adapter loom A163 540 78 10
MY2001 A163 540 12 09
The MY2001 version is similar to the MY2002 part, but doesn't have the GPS
aerial converter lead.
Mercedes C-class (W203) and CLK (W209).
The original wiring loom is available which includes the auxiliary audio
input connector and wiring. It does not include the GPS cable or the
reversing signal, so should not be used on the ML.
New C/CLK Adapter loom RHD A203 540 10
New C/CLK Adapter loom LHD A203 540 09
The new loom has the C1/C2 connectors for COMAND, the power connector for
the CD player at one end, and connectors to plug in the Auxiliary audio
input, the CAN bus distributor and the "D2B" wakeup distributor (which
connects to the other components such as phone/bose-amp/voice-recognition).
I would remove the existing wiring loom for the "C" connector, and lay in
the new harness at the same time, that way you can follow the wiring back to
the CAN distributor and the D2B wakeup distributor, which I believe are in
The CAN wires are brown/brown-red and the D2B wires are black/blue. The AUX
connector is white, and you will also need to purchase the small loom
described in the "Auxiliary Input" section below.
Other Mercedes vehicles.
You need to make a cable up that goes from the C connector on the vehicles
wiring harness to the C1 and C2 connectors on COMAND.
I suggest that you either purchase the ML adapter and add the wiring for
the reversing signal and the speed signal to it, or purchase the C/CLK loom
and obtain the C connector (Male) to plug into the existing C connector -
note that the C connector (male) may be hard to obtain.
Buying the loom is a slightly more expensive way of doing this then
purchasing the individual components and assembling it yourself, but the C
connector (male) is often not available. If you start with the ML adapter,
you will just need some pins, connector contacts and twisted pair cable.
These are the parts you need: -
A016 545 36 26
C connector (male)
A018 545 19 28
Pins for above
A034 545 75 28
C1 connector block
A000 545 42 30
C2 Connector shell
A001 545 48 40
C2 connector block
A008 545 55 26
C1/C2 connector contacts
Assorted 30 cm sections of different colour cable
30cm Piece of one-pair twisted pair
You have to make the following connections :-
C pin 1
C2 pin 9
C pin 2
C2 pin 8
C pin 5
C1 pin 6
CD Changer +
C1 pin 5
CD Changer -
C2 pin 10
A = These two cables must be twisted pair (to prevent signal
interference). If these are the wrong way round, all sort of electrical
things may misbehave. It has been reported that some cars are wired the
other way round, so it may be worth comparing the cable colours.
Note, the colours shown above are those found in the C (203) class. On CLK
(for instance) CANbus high is black/white and CANbus low is Black, sometimes
CD+ is black.
You may also want to add the following wiring when making the loom. These
are useful when using a COMAND system that was not the correct one for your
vehicle or if making a loom to use in the ML
C2 pin 15
C2 pin 6
5.1) Diagnostic Connection
In order for the dealer to configure the COMAND system the head-unit must
connect to diagnostic connector.
Older European vehicles (pre 2001/2002, except ML, A and new C class) have
a large diagnostic connector under a circular cover in the left or right
fusebox under the bonnet.
Newer cars have a 16pin OBDII connector somewhere on the panel above the
driver's legs (beneath the steering wheel) - it has a cover on it, and is
approximately 2 inches by one inch.
Nothing has to be done if you have the OBDII connector as a cable is already
connected between the COMAND and pin 12 or 13 of this connector, however
with the older connector a connection must be made between pin 2 of the A
connector at the COMAND unit and pin 34 of the diagnostic connector.
If your car had a standard radio, then the cable will already go from pin 2
of the A connector to pin 33 of the diagnostic connector - it is likely to
be coloured grey. The diagnostic connector comes apart and the pin-insert
can be moved from 33 to pin 34.
If your car had the older APS system (with separate navigation unit), then
you will have to run a new wire from pin 2 of the A connector to pin 34.
Part numbers are :-
Diagnostic connector contact (for pin 34) A 003 545 48 26
A/B/C connector (car side) contact A 011 545 80
6) COMAND mounting Bracket
You should install the mounting bracket in the dashboard to support the
COMAND unit on certain cars - here are the part numbers for those I know: -
A 163 546 16 43
RHD A 208 546 03 43
LHD A 208 546 04 43
6.1) E-Class (W210)
Part of the plastic dash (under the wood trim) needs to be replaced, its
available for a few euros/pounds from MB dealers - there are pictures at
http://www.megacomm.de/ explaining how to do this.
6.2) CLK (W208)
Many CLK's have a divider between the two DIN slots, this can be cut out
carefully, or again part of the dash replaced - its easier to cut this out
on the CLK.
7) Dealer Programming
Once you've installed your COMAND, it should mainly work - however you
really need the dealer to plug in their Star Diagnosis computer and perform
various settings and configuration. They need to configure the D2B bus to
tell COMAND what phones/CD/amplifier etc is connected. And if you have a
phone etc, configure the phone settings as well. They should also check the
COMAND is correctly coded for your vehicle type, steering and seats
(leather/fabric), otherwise lighting may not work, and navigation may not
work because COMAND may not know what speed you are going.
8) Installing COMAND in other vehicles, or I bought the wrong COMAND
In order to install the COMAND in other cars, you need to do the following
a) Purchase a COMAND system that is "without CAN", or one from a ML
b) Use the wiring description above to supply power/wakeup to the MB
fibre optic CD player if you have one.
c) Ensure speed signal from car is connected to connector A pin 1 AND
to pin 6 of the C2 connector.
d) Connect reversing signal to connector C2 pin 15
e) Connect pin 2 from connector A to car's OBDII diagnostic connector
pin 13 - if you don't have a diagnostic connector, make one up it will need
+ on pin 16, ground on pin 4 and COMAND on pin 13. Then the MB dealer will
be able to configure the car if he tells it that it's a ML (163) - good luck
persuading the dealer to plug his Star Diagnosis system into a non Mercedes
If you already bought the COMAND and its not one without CAN or from a ML,
if the software on it is new enough you can try the following, it may work -
especially if the unit was from a CLK (W208).
1) Have the dealer upgrade the software on the COMAND to MY01 software
using their update disk.
2) Have the dealer "code" the COMAND using Star Diagnosis to tell it
that it is installed in a ML (W163) vehicle.
3) Ensure speed signal is connected to both as described above.
9) Auxiliary Input
COMAND can have an Auxiliary audio input - this is normally found in the
glovebox and can be used to connect a cassette/mp3/md player or other music
The input connections are on the C2 connector and are as follows: -
Right Signal 4
Right Ground 5
Left Signal 13
Left Ground 14
Shielded 3 core cable should be used with the shield connected to pin 14 of
There is a loom available from Mercedes for this, part number
A210 440 50 05
You will have to remove the connector that is on that, and then wire it
directly into connector C2 on the COMAND. It is probably easier just to make
up the appropriate loom.
If you started using the C/CLK loom, then you will need this part if you
want to use the auxiliary input.
Please take photos of what you are doing and note any errors in the above,
or parts you used on different vehicles and send them to me, then I can
update this document for all to use. I will try and answer questions sent to
me by email ( email@example.com), but I may be slow.