PRIMER ON AUDIO/NAV SYSTEMS - GENERAL INFO, REPLACEMENT, UPGRADE, AND ENHANCEMENT

The Basics: Copper wire, D2B and MOST system differences, and what's a CAN Bus?

The first step in understanding your system is knowing how its components are connected. Mercedes vehicles have one of three basic systems interconnecting the components of their audio systems: Copper wire, the D2B fiber optics bus, or the MOST fiber optics bus. Some systems are hybrid; they may use copper wire and an amplifier in the head unit to run the front speakers, and a fiber optic connection to a separate amplifier for rear speakers and a sub woofer. The fiber optic systems are also tied into a CAN Bus, which allows control from the steering wheel and display of functions on the dashboard. All of the systems use copper wire to power individual components; and all use copper wire between the amplifier and the speakers.

Copper wire systems:
Many Mercedes vehicles before 1999 employed systems in which all of the components were connected via copper wiring. Most 3rd party head units, amplifiers, and audio processors were and are still copper wire systems. Therefore, upgrading to a new head unit, adding an amplifier, or an audio processor as simply a matter of providing power to the unit and connecting it in the proper sequence in the system. Most consumer audio shops are able to handle this kind of installation.

Fiber Optics:
Fiber optics "wiring" differs from copper wiring in that fiber optics leads ("wires") are comprised of glass or polymer (plastic) fibers that conduct light, whereas regular wiring uses metal - most often, copper - to conduct electricity. A fiber optics system will use devices that convert electrical signals to modulated light; and with different modulations, or coding, for each device, multiple devices can use the same "wire." The equipment on the fiber optic busses would include COMAND and navigation systems, Audio 10, 20, 30, and 50 units (used where the car lacks COMAND), cell phone, CD changer, satellite radio, voice control - basically anything connected to or playing through your audio system. The fiber optics system Mercedes uses are either D2B (Digital Data Bus or sometimes Domestic Data Bus) or MOST (Media Oriented Systems Transport). If you don't know which you have, see post 5, http://www.benzworld.org/forums/audio-telematics-forum/1439410-do-i-have-d2b-most.html#post3434579 or see the phone bulletins links at the bottom of this post.

D2B Bus:
Mercedes came out with its proprietary Digital Data Bus (D2B fiber optics bus) as early as 1996 in some models, and placed it in wide use for the 2000 model year (’99 in Europe). Mercedes licensed D2B to Volkswagen and Jaguar for some cars, but it was mainly used in Mercedes cars. As a result, the market is fairly small, compared to the entire auto industry, and 3rd party developers do not place a lot of effort into making upgrades for it. Any audio component in the system must connect via D2B fiber leads; equipment made for copper wire systems (and MOST fiber optics systems, discussed below) cannot be added to a D2B system; only equipment manufactured for a D2B system can be used on a D2B bus.

In addition to the requirement that the equipment be designed for D2B, each piece of equipment on or added to the bus (or “loop”) must be “version coded” in the D2B Controller. Version coding is somewhat like telling a Windows computer BIOS that a new piece of equipment has been connected, so that it will be recognized, and all of its functions enabled. Version coding is done via Mercedes DAS, a laptop computer with Mercedes-specific software that allows technicians to make settings in the many computers that control the car’s functions. If a component is removed from the fiber optic bus without connecting the fiber optic leads that went to the component (see posts 7 and 8, http://www.benzworld.org/forums/aud...399151-2000-s500-w220-chassis-how-bypass.html), the entire system will shut down.

An excellent source of information on the basic connections, and the components in the D2B loop, is in the phone bulletins in the link at the bottom of this post. Generally, Mercedes models from model year 2000 in the U.S., 1999 in Europe, through 2003, were equipped with a D2B bus. However, Mercedes began to transition to the newer, more capable MOST bus in SOME 2004 models. The first page of the phone bulletin will tell you whether you have a D2B or a MOST bus, by mentioning notes pertinent to the bus. You can also identify the type of bus in your car by looking at the fiber optic connectors – see post #2 at http://www.benzworld.org/forums/audio-telematics-forum/1439410-do-i-have-d2b-most.html#post3434579.

For a detailed technical discussion of the D2B bus, see https://web.archive.org/web/2012022...Telematics/416 HO D2B (CooksonI) 03-09-04.pdf

MOST bus:
The D2B Bus was succeeded by the MOST (Media Oriented Systems Transport) fiber optics bus beginning with Model Year '04 (later in some models). MOST is a more capable bus, and rather than being proprietary, is an automotive industry standard used by many manufacturers. As a result, there are far more options manufactured for it, and MOST is still in use in the newest Mercedes cars. You cannot use equipment designed for one type of bus with the other. Again, the phone bulletins at Phone Bulletins will help you identify which system your car has by model year. All Mercedes passenger cars since MY 2005 have had the MOST bus. If you are inclined, you can also read a great deal of technical information on the MOST bus (and comparisons with D2B) at https://web.archive.org/web/2006090...elematics/416 HO MOST (CooksonI) 07-01-04.pdf and once again, if you wonder which type of system you have, you can determine it from the fiber optic connectors – post #2 at http://www.benzworld.org/forums/audio-telematics-forum/1439410-do-i-have-d2b-most.html#post3434579. Just as with the D2B system, leaving a fiber optic loop open when equipment is removed will cause the entire system to shut down. The loop must be closed with a coupler (bypass) - posts 7 and 8, http://www.benzworld.org/forums/aud...399151-2000-s500-w220-chassis-how-bypass.html.

Again, for a detailed discussion of the MOST bus, see https://web.archive.org/web/2006090...elematics/416 HO MOST (CooksonI) 07-01-04.pdf

CAN (Controller Area Network) bus:
Among many other functions, the CAN-B bus allows your steering wheel buttons to control components of your audio system, and also relays the information from the equipment on the fiber optic loop to the instrument cluster, so that it can be shown (usually on a multifunction display). It is used in cars with both the D2B bus and the MOST bus. Other CAN busses exist - CAN B is the interior bus, and is connected to the audio system; CAN C is for the engine; and CAN D is the diagnostics bus. These are copper wire electronics busses, and they communicate with each other and with the fiber optics bus when necessary through devices called "gateways." In simplest terms, CAN busses help various controls, sensors and displays operate. When you replace an original equipment Mercedes head unit with a 3rd party unit, that unit will probably not have CAN-B connections, and you will lose steering wheel button control and instrument cluster audio, navigation, and phone displays. There are 3rd party devices that can be installed to restore some of these functions, but they must be matched to the car’s CAN-B bus and to the head unit as well.

For a detailed technical discussion of the various CAN busses, see https://web.archive.org/web/2014081...507 Systems I/507 HO CAN B (ICC) 10-28-02.pdf and https://web.archive.org/web/2013041...isor/219 HO Networking (ACB-ICC) 09-03-02.pdf

3rd Party Replacement Systems

Replacing MOST fiber optics systems:
In the recent past, replacing an original equipment head unit meant replacing the entire fiber optic bus, and all of the equipment on it. Generally, here is what you are getting into if you replace your Original Equipment COMAND system or head unit with 3rd party equipment - http://www.benzworld.org/forums/w220-s-class/1618981-removing-command-system.html. Many modern head units in fact offer the same or better capability than what you lose – but the expense of the head unit, a good audio processor, a new amplifier, and possibly new speakers is often prohibitive, sometimes approaching $5,000 or more - but it can be done. Still, the capabilities of modern head units that replace decade-old audio, navigation, and phone capability, and adds DVD viewing capability, may justify the cost to some.

Advantages of a 3rd party head unit over older Mercedes COMAND (2.5, 2.0, MOPF, NTG 1 and 2) and Audio 50 units include better navigation displays; navigation to specific address rather than to the block; better Bluetooth compatibility, including better contacts download and superior “Yellow Pages” (POI) functions; ability to look up a “Yellow page” entry, plot its location on a map, and call it as well; better music player compatibility (including iPod, iPhone, Android phone, and other mp3 player capability, and including A2DP Bluetooth audio streaming); ability to access and run iPhone and Android apps on the head unit; satellite radio; ability to view DVD video while in motion and other capabilities. High quality double-DIN head units as well as single-DIN units with pop-up screens are available from manufacturers such as Kenwood, Alpine, Pioneer, Panasonic, and JVC, to name only a few.

But replacing a MOST COMAND system just got a lot easier. One developer has announced a first-of-kind analog (copper wire) to digital (fiber optic) converter that allows Mercedes COMAND or other head units to be replaced by a variety of 3rd party head units, without replacing the amplifier or speakers, and without need of a separate audio processor. In addition, several devices are available to preserve steering wheel button function with some 3rd party head units. See the discussion of the OPTI-1 analog to digital conversion unit at http://www.benzworld.org/forums/aud...4297-replacing-comand-just-got-easier-mb.html and http://mbworld.org/forums/audio-electronics/466505-replacing-comand-just-got-easier.html - and be sure to follow the imbedded links in each for sources, extensive discussion, and even some installation experience with this new product. The OPTI-1 (now marketed by Nav-TV as the MOST-HUR) is compatible with a variety of excellent 3rd party head units, and can also be used together with kits that preserve steering wheel button function. Without the need to buy separate audio processors, amps or speakers, the cost of replacing an OE COMAND unit is far less than replacing the entire system.

Replacement of D2B systems:
As of now there is no analog to digital converter such as the OPTI-1 for the D2B system. One is still left facing the considerations of full system replacement discussed at http://www.benzworld.org/forums/w220-s-class/1618981-removing-command-system.html - there are some units of Chinese manufacture that claim to be available for replacing D2B or MOST COMAND units, but I have no experience with them; see http://www.benzworld.org/forums/w220-s-class/1653686-dvd-gps-player-system-china.html and http://www.car-audio-dvd.com/replacement-benz-sw220-s280s320-s350s400-s430s500car-dvd-p-19.html - the product website claims these units maintain the CAN Bus connection. I am unclear from the website just whether and how connections are made to a fiber optic amplifier.

In addition, if one is adding a 3rd party system having navigation capability to a car that did not have navigation before, it may be necessary to add a wheel speed sensor, depending on the 3rd party system being installed.

Copper Wire Systems:
Replacement of copper wire systems is fairly straightforward, and depend mainly on how elaborate a system one wants. One can retrofit 3rd party double-DIN systems, single-DIN systems with pop-up screens, or single-DIN systems with either a small screen or only a display panel. Modern copper wire replacement systems can be purchased with the same capabilities as those for MOST and D2B systems, and in many cases, are exactly the same equipment. See, for example, http://www.benzworld.org/forums/r-c107-sl-slc-class/1643707-107-audio-thread.html and writeups in other vehicle specific sub-forums. In addition, many owners of collector or vintage cars may find that they have newer radios whose appearance does not suit their cars; vintage-look radios are also available. As just one example, see the posts and links beginning at #27 , http://www.benzworld.org/forums/r-c107-sl-slc-class/1643707-107-audio-thread-3.html

Adding a 3rd Party Head Unit with COMAND-Like Features
There are many modern head units that offer navigation (either built-in or as options), Bluetooth telephony, A2DP music streaming, DVD viewing capability, and the ability to utilize apps from a cell phone. Many of these are Japanese, some are Chinese. Some units will allow use of steering wheel controls, others do not. All of the Japanese units at the time of this writing are copper wire systems, and would require installation of additional equipment. Some of the Chinese units offer both fiber optic and copper wire output options. Some members have reported very poor reliability, difficulty with installation, and poor customer service with some of the Chinese units. THE EXCEPTION is Avinusa, which has been a supporting vendor. Members have reported excellent support from Avinusa for the units they sell. Contact [email protected] for more.

Member Rossafuss has pointed out an Android-compatible COMAND type unit vailable for many Mercedes models, including fiber optic systems as well as non-fiber optic. However, with a fiber optic system, to retain the other components of the system, an additional adapter is required; and as of this writing, the site does not make it particularly easy to match the head unit to the car. The info is there, but you'll do some digging fre each HU. See http://xtrons.com/head-units/custom-special-car/car-make-l-r/mercedes-benz.html?p=1. See his original thread at http://www.benzworld.org/forums/aud...ommand-replacement-market-just-massively.html. There are also rear seat systems, backup cameras, and fitment kits. In addition, see Dave 2302's excellent writeup on the topic in the W220 forum, beginning at about post 272 and going through 305. http://www.benzworld.org/forums/w220-s-class/2693609-s500-resurrection-daves-thread-28.html

Upgrade of Existing Systems

Upgrade usually encompasses adding other Original Equippment components to an existing installation, or adding a separate amplifier and subwoofer to an existing system. Adding capabilities to OE systems for cars that did not have the capability is accomplished by purchasing the proper part number that the car would ordinarily have had, connecting it, installing any necessary fuses, and version coding the fiber optic controller so that it recognizes the new addition. For one such example, see OEM Navigation Retrofit w/ pics - MBWorld.org Forums. In MOST systems, the fiber optic controller is the Audio Gateway (AGW). For D2B systems, it is the head unit itself.

For both D2B and MOST systems, one of the simplest upgrades is the addition of a separate amplifier and subwoofer to the existing system. The easiest way is to wire the additional amplifier to the sub-out speaker leads on the existing amp, using either a line output converter if the sub's amp lacks speaker level inputs; or perhaps best, use a sub amp with speaker-level input. Also: You will need to find a good location for the subwoofer, and may have to open a port into the passenger cabin to experience the additional bass. Be aware that removing the existing rear deck subwoofer may be extremely difficult without destroying it, and some OE subwoofer assemblies have additional speakers in them (this is certainly true of the W220!). One member has suggested a fairly expensive but apparently successful approach HERE.

Member Rossafuss has pointed out an Android-compatible COMAND type unit vailable for many Mercedes models, including fiber optic systems as well as non-fiber optic. However, with a fiber optic system, to retain the other components of the system, an additional adapter is required; and as of this writing, the site does not make it particularly easy to match the head unit to the car. The info is there, but you'll do some digging fre each HU. See http://xtrons.com/head-units/custom-special-car/car-make-l-r/mercedes-benz.html?p=1. See his original thread at http://www.benzworld.org/forums/aud...ommand-replacement-market-just-massively.html. There are also rear seat systems, backup cameras, and fitment kits.

MOST systems:
If you are adding an OE Mercedes COMAND unit to a car originally equipped with an Audio 50, 30, 20 or 10 head unit, the best resource I know of is Richard Almeida’s wonderful work at http://www.mercupgrades.com. Richard’s searchable site has part numbers, retrofit instructions, and a wealth of other information on COMANDs for most MB models. You may also find Wolfgang’s page at Mercedes Radios and Navigation to be helpful. In addition, the sticky at http://www.benzworld.org/forums/audio-telematics-forum/1402593-w211-new-comand-2008-2009-a.html discusses upgrading the MOST COMAND 2.0 and some Audio xx systems to a newer version COMAND, the NTG (Next Telematics Generation) 2.5 unit.


D2B systems:
Many forum members have wanted to replace their COMAND 2.5 systems with something having wide screens and more modern, DVD-based navigation, and have asked if they can retrofit a COMAND unit from a MOST-equipped car. The answer, unfortunately, is no. However, it is possible to upgrade the older COMAND 2.5 units to wide-screen COMAND MOPF units, and one member of this forum has shown the way: http://www.benzworld.org/forums/audio-telematics-forum/1472758-w220-my-swap-comand-2-5-a.html; but the principal advantage of this upgrade is simply the wide screen appearance. The COMAND MOPF functions exactly the way the narrow screen COMAND 2.5 does, and remains CD-based. Once again, Richard Almeida’s site at http://www.mercupgrades.com remains invaluable to any such upgrade.

Also, see the note on 3rd party head units from Avinusa in the preceding section.

Voice Control:
It is also possible to upgrade the first-generation Voice Control module (MY ’00) to gain more control over your system; this is particularly easy if you already have a VCM installed. See http://www.benzworld.org/forums/audio-telematics-forum/1193674-update-voice-control-2000-s500.html

Navigation Systems:
One question unique to the COMAND 2.5 systems relates to the navigation CD sets. Although not related to audio specifically, the first COMAND 2.5 units used a unique file format on their navigation CDs, and had what was called “C” navigation. Near November of 1999, COMAND 2.5 units using the “D” navigation discs, with an entirely different file format, came into use. The file formats, and therefore CDs, are not compatible between the two; and the “C” disc set for the U.S. and Canada has not been updated since 2004. To tell which type of system your MY ’99 (Europe) or 2000 COMAND uses, see post #2 at D-Nav? - MBWorld.org Forums - and be aware that the wide-screen COMAND MOPF uses “D” nav discs. Cars equipped with the MOST bus use DVDs rather than CDs.

Hands Free Phones (Bluetooth):
Since many states now require that use of phones be hands free, see http://www.benzworld.org/forums/aud...13173-how-guide-cell-phone-upgrades-plug.html - once again, not strictly audio, but it is an often-necessary upgrade to both D2B and MOST fiber optic systems.

Also, see the link in post #1 , http://www.benzworld.org/forums/aud...io-introduces-bluetooth-cassette-adapter.html for a tape deck cassette that promises Bluetooth music streaming and telephony for cars having a cassette deck.

Adding SIRIUS - specific receivers are made for the cars that can have SIRIUS integrated with OE head units. See post 2, http://mbworld.org/forums/audio-electronics/332955-sirius-receiver-part-numbers.html for the listings. Receivers for one model will likely not work in another.

Enhancement of Audio Systems

Because the MOST bus is now industry standard, there are more enhancements available for it than for D2B systems.

MOST System Enhancement:

Adding an iPod or other music player:

Mercedes itself offers an iPod integration kit for some MOST-equipped cars. The car must have a 3.5mm AUX input before the system can be used (this excludes, for example, the ’04 through ’06 S-Class, and possibly other models as well). When available, the MB kit offers full integration, including display of song title, album and artist information on the instrument cluster (NOT on the COMAND display), as well as steering wheel and head unit control of the iPod. However, use of the 3.5mm jack (whether with the MB iPod system or not) can result in loss of audio quality - see http://mbworld.org/forums/audio-electronics/234260-oem-ipod-adapter-vs-dash-cd-vs-gateway-500-a.html.

Dension, Nav-TV, mObridge, mCar and possibly others make fiber optic gateways for full integration of iPods (including iPhones) and other music players. The Dension Gateway xxx units have provisions for iPod, for RCA, and for USB inputs. Some Gateway xxx and mObridge units have provisions for Bluetooth phone capability and A2DP (stereo music streaming over Bluetooth) as well. Similar capability is provided by mCar. Nav-TV makes a range of fiber optic gateways that range from simply adding an AUX input capability to providing full integration of music players and phones. A new product recommended by one owner is the GROM MST4 - http://gromaudio.uk/media/grom_application_guide.pdf

The benefit of using a fiber optic gateway for such integration is superior sound quality when compared to the 3.5mm stereo jack that some cars have (often located in the glove compartment), and control of the iPod or USB device from the steering wheel and head unit buttons (control via the RCA inputs is not available). For further discussion of a Dension Gateway 500 installation, see https://www.benzworld.org/forums/au...1319829-gateway-500-most-not-ready-prime.html. Installation instructions for mObridge units are on video, and are easier to understand than those for the Dension units. See mObridge | Bridging media, communication, and lifestyle with your vehicle and also NAV-TV for more. The COMAND unit for MOST bus is text-capable, and all three units will display song title, artist, and album information on a COMAND screen (I do not know if it will do so for Audio 50 or other units). Limited track information is available on the instrument cluster multifunction display.

Be sure, however, to double check vehicle compatibility before ordering or starting to install these units. The differences can be subtle – for instance, a recent note on the Dension site observes that a particular gateway unit (the GW 500S BT) is not compatible with COMAND units having red and green telephone “send” and “end” buttons. That's fairly subtle and easy to miss.

Also, until a year ago, a fourth supplier, CarTronics of Atlanta, GA also sold iPod and Bluetooth systems for Mercedes under the iTronics brand. Unfortunately, the owner passed away, and one can no longer order from them.

However, as problematic as installation can be at times, these units offer superb sound quality and are significant improvements over CD changers, mp3 DVDs, and FM radio, for music. Contributor Floobydust has written an excellent analysis of the sound quality using various audio inputs, at OEM iPod Adapter vs. In-Dash CD vs. Gateway 500 - MBWorld.org Forums.

D2B system Enhancement:

Adding an iPod or other music player:

Only Dension, www.dension.com, offers iPod integration for D2B-equipped vehicles. Unfortunately, D2B COMAND units are not text-capable, and song title, artist, and album information is not available. Limited track information is displayed on the COMAND screen. One can control volume, and can scroll through tracks using the steering wheel controls. However, the best way to set up the system is to organize the music into playlists; then, before driving, choose a playlist. Once that is done, one can scroll within the playlist. Track numbers in the system are not necessarily accurate, and mainly serve to show that the song has changed.

The Mercedes Player MP40 is an MP3 device that can replace the CD changer in D2B equipped cars, and claims it can do so in many models from 1996-2005; see Mercedes Player MP40 - Mercedes Player. The MP40 uses solid state media cards of several different types for music storage.

For D2B AND MOST Systems:

Adding A2DP Music Streaming:

As mentioned above, some systems from Dension, mObridge and Nav-TV offer A2DP (stereo music streaming over Bluetooth) in some of their fiber optic iPod integration units. However, members have also tried adding an A2DP “dongle” to a 30-pin iPod connector in an existing system. See https://www.benzworld.org/forums/au...2dp-bluetooth-streaming-please-help-what.html and Iphone 3G using A2DP connected to Pioneer car audio deck - MBWorld.org Forums. SkippyJasper got one to work, but the pairing of both the phone and the A2DP seems a bit of a challenge - https://www.benzworld.org/forums/audio-telematics-forum/1694956-can-i-connect-merc-s-bt.html - and williamhop102 provided this at post#4, https://www.benzworld.org/forums/au...h-streaming-please-help-what.html#post5748683 - ViseeO has come out with the Tune2air A2DP Bluetooth dongle that plugs into a 30-pin iPod/iPhone connector - http://www.viseeostore.com/products/mercedes-benz.html/ - We could use more information on this type of device. ViseO also has a WMA-3000A device for cars having the Media Interface or Media Interface Plus that allows for Bluetooth music streaming.


Some owners have reported success adding wi-fi "hot spot" equipment to their cars and using either a USB input or the 3.5mm stereo jack, if the car has one. See http://mbworld.org/forums/audio-electronics/497406-a2dp-glovebox.html

Last, for cars having a cassette deck, see the link in post #1 , https://www.benzworld.org/forums/au...io-introduces-bluetooth-cassette-adapter.html for a cassette that promises Bluetooth music streaming and telephony. More at http://www.ionaudio.com/products/details/cassette-adapter-bluetooth - ION says it is available for about $30, and, Bradm says a similar item is now available from Radio Shack for $49.95 (first link).

Software Enhancements:

One can use one of several software enhancements, either through an iPhone, an Android phone, or an iPod Touch. Developers such as SRS Labs, BBE, and AudioForge have offerings, and the list will likely expand. See https://www.benzworld.org/forums/audio-telematics-forum/1653757-neat-music-enhancement-app.html for some of the software apps - also, post # 19 in that thread suggests an excellent way to transfer a custom EQ setting to an iPod, and makes a recommendation on specific settings. Yours truly is using that EQ procedure in that post right now, and it works wonderfully in the Bose audio system in my W220. And contributor poopbunny (yes, that’s his screen name) has some additional suggestions for tweaking the custom EQ settings, especially useful if the speakers have been replaced or upgraded. Mike5215 has recommended the AudioForge EQ app, at https://www.benzworld.org/forums/w220-s-class/1725225-big-audio-upgrade-4-99-a.html

Hardware Enhancements:

If you have a 3.5mm AUX jack, you can accomplish enhancements through hardware. Mike5215 has contributed an inexpensive hardware EQ enhancement for cars that have an AUX input, at https://www.benzworld.org/forums/audio-telematics-forum/1760993-upgrade-your-sound-easy-mod.html - his installation in a W221 is nicely documented. He uses the hardware device in combination with the AudioForge EQ app mentioned above.

One member has suggested use of a high-end digital sound processor and some (optional) speaker upgrades HERE.

Mirroring iPhone and Android phone screens on COMAND Member hilarushi has posted that link for mirroring iPhone and Android phone screens onto the later model Mercedes COMAND screen; Video In Motion is also required (I have used the NAVIKS VIM device, though separate from the video mirroring, and it worked well).

Apple CarPlay, Android Auto, and Current Nav Data on COMAND Screen

With the death of the nav updates for the NTG 3.0 and 3.5 systems in the 2007-2013 S-Class and CL, I started looking at other alternatives. There are several ways to get smart phone data displayed on your COMAND screen. That can include the maps, including those with turn-by-turn instructions, often used in iPhones, Android phones, and iPads. It can also include running other apps, in addition to maps.

One solution was presented by member hilarushi at https://www.benzworld.org/forums/au...5-mirroring-iphone-android-phones-comand.html - it is a wireless solution using the phone as a wi-fi hot spot transmitting to a wi-fi rebroadcaster (such as Anycast) with an HDMI output that in turns feeds into a device that converts the HDMI output to analog RCA output (https://www.amazon.com/s/?url=searc...h=n:15684181&field-keywords=HDMI2AV+Converter), in turn feeding into the MMI aux inputs that can be selected and displayed on the COMAND screen. One would have to use that somewhat balky setup with a Video In Motion device (I would recommend the one by NAVIKS, having used one for a brief time). The setup can be used with either iPhone or Android.

A second method is wired; using an Apple Lightning to HDMI output cable (https://www.apple.com/shop/product/...cadc2c02fbd989c4e20d6a519f778df5c5f5782896ea6), one that then connects via an HDMI cabe to the same HDMI-to-analog device used in the wi-fi connection above. Selection of the RCA video is again made on the "Video" menu of COMAND. I do not know if iPhones having 30-pin output will work as well, but there are a number of HDMI adapters for various Apple devices. I have not explored similar cables for Android.

A third method is to use a video interface such as that by NAVIKS - https://naviks.com/i-24075303-2010-...ss-w221-hdmi-video-integration-interface.html. It is also used together with an iPhone HDMI interface, and North American cars require a Video In Motion bypass device as well (https://naviks.com/i-21933022-2010-2013-mercedes-benz-s-class-w221-video-in-motionbypass.html). All together, including additional cables, etc., your'e looking at nearly $650 for a DIY installation.

All of those methods transmit audio together with the smart phone map display, so you can get turn-by-turn instructions. None of the methods offers nav data on the multifunction display - only on the COMAND screen. The first two methods involve a bundle of unsightly wires that would need to be hidden, and require a power source. Frankly, I would only use such a setup if I were traveling in an area I am totally unfamiliar with, and I'd be tempted to do it just using an iPad instead of using all that stuff.

There is also a fourth method, which actually involves replacing the OE COMAND monitor. It involves a replacement unit (the monitor, in any case) for COMAND 3.0 and 3.5 that offers Android compatibility, but as yet it does not say it offers Apple CarPlay (though because it turns your monitor into a wi-fi hotspot, it probably does). https://www.sardincar.com/mercedes-...roid-gps-navigation-system-multimedia-player/.There is much more at https://mbworld.org/forums/s-class-w221/710915-w221-android-touchscreen.html (you'll have to sort through some snarky posts - sorry) - but this site says its unit offers both Android Auto and Apple CarPlay compatibility (via a 4G hotspot). I have no experience at all with this system, and the first website (at the time of this post) does not provide pricing; the second indicates about $675. I do not know if this unit is for the CL. I also do not have a website that allows ordering; MBWorld member Chris The Swede, who participated in the referenced links, is apparently somehow connected to sales, but must not say so outside of PM.