Comand NTG 2.5 Retrofit Installation guide – on a E211 (2004) with Audio 20/Single CD!


Doc Version 1.1 – Dec 29th 09 – Visited my local Merc garage and got the Speedometer integration enabled (more details in relevant section).


Notice for the doubters out there!


Due to the numerous combinations of what will and what won’t retrofit, here’s an installation guide of what was in my car and what I fitted. I hope the ‘numerous combinations and doubters’ will be ‘mainly’ wrong and this guide will actually cover many other W211 retrofit combinations …

My car

…Is a (April) 2004 E220 CDi Avantgard estate with 5 speed manual box. UK spec’d right hand drive.


It does NOT have the pre-wiring for a phone (apparently this is important otherwise its more difficult to retrofit the Comand).

Audio pre retrofit

It had an Audio 20 (Radio) Single CD. The Model number and Part number on this device are/were  - A211 820 98 89 and MF2311.

There was no CD multi-changer anywhere in the car. This meant the storage bin behind the panel with the Hazard buttons/rear headrests/central locking was a useful storage area (but no more…read on).


The Audio 20 and steering controls had all the Telephone buttons there, but None of it worked as my car did NOT have the telephone wiring. If I pressed any of the Telephone buttons on the Audio 20 or the steering controls, I’d get a message along the lines of ‘No phone’ or ‘Function not available’.


Note: I’ve read, so can’t confirm, that if the car did have the Telephone pre-wiring, then the Retrofit would have been harder to achieve/implement.

Comand NTG 2.5 and bits required

  • I bought the NTG 2.5 off (sharp intake of breath) eBAY from an England based guy – didn’t want to risk any of the foreign sellers, but would have saved a packet!

    It’s model number is A211 870 50 94 Made in Japan (2008)

    If the wife’s reading this it cost me £250 – ahemm….
  • Sat Nav aerial (included with purchase of Comand)

·        NTG 2.5 adaptor cable - £30 from another eBAY England based seller.

The following 3 items were bought from for £135

(Email them with what you have, and they’ll Email you back with hyperlinks to what you need from their website)

IMPORTANT - You can’t cut corners with these items as the connectors on the back of the device are key coded i.e. have different lugs for each connector, so you need the proper connectors fitted to install without having to hash a DIY messy job.

  • Bluetooth aerial
  • Microphone
  • Radio aerial lead adaptor


  • [Optional] If you want Navigation data in the Speedometer window, visit your local garage that’s equipped with the Mercedes STAR system. I did go ahead with this and it cost me a half hour’s labour £54.60 all-in (and I got an included car wash and hoover out!!).

    This visit allows the new Comand to display its Navigation data in the Speedometer electronic display.

    NOTE: All existing functionality (pre retrofit) with my Audio 20 device was still there before the visit to the garage, including the Radio channels information – this had not changed since retrofitting.


Optional things to do for an absolute complete job, but I’ve not done it…

  • Linguitronic  - voice control – I’ll probably not go for this.
    Although you can do the Linguitronic/voice control tutorial on the device, you won’t be able to use it to control the device unless you buy a separate control lever that fits onto the steering column – you press this when you want to use the voice control functionality. I didn’t think it worth the cost to do this as all the other functions are available from the device’s front buttons/panel. Maybe if I win the lottery…

Features post retrofit – and limitations!

I now have, confirmed working –

  • Sat Nav with Europe map – voice guidance also comes over the speakers.
    It also includes TMC facility which superimposes traffic congestion of major roads (shows Red cars on the road route if particularly busy (<10 mph), Yellow for high traffic, and a Readable list of what roads have roadworks/accidents).

    It includes Full address or 7 digit Postcode entry – albeit a bit fiddly – I suppose the Lingutronic/Voice control would help here.

    The map is old, and from what I’ve read on forums, very expensive to update. I’m also bewildered as to which map/DVD I’d actually need as there are many formats and versions to keep you on your toes…Does anyone have an idiots’ guide to which update disc is for which Comand?

    [Optional] I visited my local Merc garage and got them to enable the Speedometer display to show my Navigation commands. There are 2 benefits now – 1) Navigation information within the Speedometer display and 2) When the Navigation is not in ‘Show me directions to destination’ mode, it displays your current Heading (N, S, E  W format) and the current Road/Street name – quite useful. (To display this Navi information, the Speedo display needs to be in Navi mode using the usual steering controls – the ones that cycle between MPG, Speed, Radio, Temperature etc)

    I’d still rate a portable Tom Tom better than the Comand for usability and presentation, but it’s not integrated into the car…

  • Telephone integration via Bluetooth – which I rate as very good.
    I have a relatively old Samsung SDH-D900i which ‘pairs’ successfully and automatically when I enter the car. Folk on the other end of the line say I come through loud and clear, not like some car Bluetooth devices which sound awful.

    Contacts transfer to Comand unit - with my phone I can’t get this to work, but on my daughter’s Sony Ericcson it will work – looks like its fussy about which phone you use. With my mobile attached, the transfer buttons are there on both the Comand and my phone, but they’re either greyed out or simply don’t do anything. This just means I have to do a one-off manual entry of each of my Contacts that I want into the Comand’s memory.

    NOTE: I visited my Merc garage to have the Comand showing its Navigation information in the Speedo display – I was hoping this would have also have got the phone buttons on the steering wheel working, but NO. The technician was saying these buttons are hard wired for a car with ‘telephone pre-wiring’, and if it isn’t fitted (like mine), it’s not a STAR/programmable option.

  • Radio – FM only though! – This is the area that’s the most surprising as I would have thought this was a no brainer / easy option to get working.

    I’d read that radio reception was poorer on a Retrofit, and I can confirm this is the case.

    In a strong radio signal area, the Comand radio works very well and has the nice feature of showing ‘ye olde style’ radio dial of each station available in the area, with a vertical bar that’s moved with the arrow buttons to move to those available radio stations on display. It works well and updates constantly as stations come and go out of range. Due to the poorer reception capability, the screen can go eerily empty when in a poor reception area.

    Techie radio connection findings:
    The Comand has a dual-headed aerial input (see photos). This needs the aerial conversion lead which does this conversion. I queried the reception with the lead supplier,, and they said I should try just using the FM aerial input. I’ve interpreted this as meaning only allow one of the dual head connectors to be fitted, leaving the other disconnected and dangling out the back of the connector. Looking at the back of the unit if you kept the right hand lead in, and quickly powered up the Comand, there’s no FM reception, so I though to myself it must mean the left hand connector is for FM, and the right for AM/SW/LW. Once all fitted into the car again I ran for a couple of days with just the left hand connector plugged in. For FM, this was actually worse – all I could get was the one station listed, with no multiple stations showing on the screen so I’d have to manually tune it in to another station. Reconnected both leads to get the full screen station listing working again.

    Summary of Radio operation - The Comand needs both of the dual head radio adaptor connections plugged in – I can only speculate that its like Sky+, in that one input is for the currently tuned FM station, and the other input does the background scanning of what else is available in your area. I also found that AM/SW/LW simply DO NOT WORK, not even a hint that there’s a station there – no loss to me as I don’t listen to them, but important if you do!!

    I guess it also means there’s another input on the back of the Comand for AM radio signal – does anyone know?

  • DVD video playback – Looks impressive, but a pure ‘toys for the boys’

    Plays copied DVD video as well, so good compatibility. It also blanks the picture once you go above about 10 mph for safety reasons.
  • CD / SD card music player – Not tested this, but no reason it won’t work.

    Since the Comand has a 4GB hard disc, it’s got the facility to copy music to the hard disc, but I’ve not tested this, no reason why it won’t work – not that I’d probably use it – I’m a radio man.


Storage area behind panel with Hazard button/central locking/rear wash wipe

I’d read on forums that this area stops working after a retrofit upgrade, and I can confirm this is the case…I liked the ‘hidden’ compartment.

Apparently its something to do with this area being the optional CD multi-changer area, if fitted, and since Comand doesn’t need it, the cable adaptor must leave out the pins that supply the signal/or power for this to work.


I’ve read a DIY guide that shows you how to get this working again, but its fiddly and doesn’t use the existing button – instead it has you fitting another toggle switch (in this example hidden in the glove compartment) – not ideal so I’ll leave this out until someone comes up with the wiring to use the existing switch.

With me visiting my local Merc garage to have the Navigation information displayed in the Speedo, I was hoping they could ‘toggle’ a setting on their STAR system that would get this going again, but NO. He even tried ‘pretending’ the car had a CD multi-changer, but still didn’t change its status. Looks like it’s the ‘fiddly’ modification that’s required if I want this to work again…


Fitting instructions, at last!


Note: For the observant among you, you’ll notice the pictures show the Comand already fitted, correct! The photos were taken when I went to remove it after the radio trials…


For comparison purposes, here’s the back of my Audio 20 - The single aerial lead on the left.

Note the ‘multi connector’ area on the top right, is the same physical format as what’s fitted on the NTG 2.5 unit, but the wiring is different, hence the need for the adaptor – be warned in case you think you can simply plug the existing wiring into the new unit.


And the back of my new NTG 2.5 –

In another photo, I list the connector purpose.


Before you fit the new Comand, you’ll need to remove 2 supporting lugs that are on the sides of the new unit, these simply unscrew – I didn’t have a before photo, so you’ll need to accept the photo of me pointing to where the right hand lug was screwed in. It won’t physically slide into the dashboard without these removed!



Remove the gear lever cover/panel.

No tools required as it simply pulls up (spring loaded retainers) from the front, then slides out at the back (next to the cup holder compartment).


Remove the ashtray – small straight bladed screwdriver required.


This is a bit awkward to show in the photo, but there are 2 retaining lugs, one each side, which need to be ‘slightly’ levered to allow the ashtray to be pulled out. Don’t overdo the leverage of the lugs or they’ll simply snap!!



And then pull out the lighting connector out (there’s not enough space to leave it dangling ) – Based on the orientation of the photo, this pulls towards the gear lever, it will show resistance, so patience and a firm hand required.


Unscrew 2 Torx retaining screws for Panel control with Hazards/ rear wash/wipe


Once the 2 Torx screws are removed, one each side of unit – left hand shown (obviously!!), this unit will simply pull forward, ready for the yellow cable to be disconnected…

The yellow cable is fiddly to disconnect, especially if its never been done before. I found it easier if you slightly separate the connectors with a small flat bladed screwdriver then pull the 2 halves apart…as per the photo…



Does anyone know what the circled 2 pin connector is for – it simply lies loose not connected to anything?? I never noticed it before and wondered if it was the reason for the Storage panel not to open after the retrofit. I’ve looked over the Storage panel and can’t find any female connectors that are missing their male connector.


Now slacken the retaining screws of the Audio 20


NOTE 1: These screws are mounted vertically, and are unscrewed until they come to their end stops, they DO NOT come out, just screwed to their end stop. I reckon about 25 turns is what they need to get to their end stops – it’s obvious when you reach this point.

NOTE 2: It’s the same Torx bit you use that was used to remove the front Panel’s 2 screws.


Connect up all the new cables/adaptors/ to the new unit


  • Disconnect the cables from the now old Audio 20.
  • Connect up the new (large) NTG 2.5 adaptor cable to the existing wiring lead.
  • Connect up the Bluetooth cable. The one supplied from will come with a sticky pad to attach the circuit board end to a suitable mounting within the centre console – I used one of the bottom panels in the gap.
  • Connect up the microphone lead. Note this is a largish white connector which fits into one of the blank areas of the large NTG 2.5 adaptor cable connector.

    I routed the microphone lead through the gap, then right to behind the steering wheel dashboard (see 2nd photo that follows this) until it comes out at the fuse board circuit on the immediate right of the dashboard – If you don’t already know, there’s a fuse box access panel on the immediate right of the dash, between the dash ending and the driver’s door. With the driver’s door open, simply pull the panel off (with the help of a screwdriver) and you should be able to see right through the dashboard to the side of the open gap you’ve just created by removing the Audio 20. I then routed the remainder of the lead behind the edging that runs up the side of the window pillar, over the sun visor, and located the microphone on the side of the roof mounted lighting pod – retained by threading it to the roof lining (see photo, although blurred).
  • Connect up the Sat Nav aerial lead, and route it the same way as the Microphone lead through the back of the dash (see 2nd photo that follows this), then up to the top of the dashboard and hide it in the convenient gap between the front window and the dash, finally resting on a double sided sticky pad in the middle top of the dash (see photo).


Now ready to slide the unit into the dash for the 1st time.


I found the bulk of the cables and NTG 2.5 conversion cable inhibited the unit from sliding all the way in, so I found that by sliding the bulky NTg 2.5 cable into the gap on the left of the open area meant it would all fit.


The second arrow, pointing to the right is where I routed the microphone and Sat Nav aerial leads for their onward journey behind the dashboard…


Picture of the Microphone and Sat Nav aerial



Now refit the units back into the centre console


  • The new Comand should fit snugly back into the centre console. If there’s much resistance, it means the cables are fouling, see my advice on tucking the bulky NTG 2.5 into the gap on the left.
    Retighten the retaining Torx screws.
  • Refit the Centre Panelthe one with the Hazard switch etc, reconnecting its electrical cable,, re-fitting its 2 Torx screws.
  • Refit the ashtray, remembering the lighting connector.
  • Refit the gear lever panel.
  • [Optional] Now visit your local Merc garage only if you want Navigation data to be displayed in the Speedometer display. I was charge a half hour’s labour to have this done.


Job Done!!


I’ve leave the fine tuning of the actual unit to yourself – I’d recommend you explore the menu functions for yourself, otherwise I’d be here for another few hours while I document the options that are there.