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Created: 29 Sep 2007

Last Updated: 29 Dec 2007

V1.1 29th September 2007

This document covers retrofitting COMAND APS to the Mercedes Benz ML (W164), to the GL (X164) and to the R class (W251) vehicles.

COMAND APS is supplied as an option in the Mercedes ML, GL and R Class in Europe and the rest of the world except North America (which gets MCS-II) and Japan which gets a more advanced system.

Retrofitting COMAND APS  to the ML GL or R Class Mercedes Benz should take less than one hour, but the car will need coding by a Mercedes dealer with Star Diagnosis afterwards.

This COMAND APS retrofit uses a retrofit antenna mounted under the dash board, rather that the original one mounted under the roof at the rear of the vehicle. If your vehicle has the infrared reflective glass, then you can not use the retrofit antenna because the glass has a metallic coating. Please see the parts notes for the parts required instead. However, this document does not cover how to fit those parts in detail as it involves removing the head-lining at the rear of the car.

Tools needed.

  1. Torx TX20 driver

Parts needed.

Amount Part Number Description and Notes
1  See my COMAND-APS parts document at
1  A001 820 7675 Retrofit GPS antenna
1  A211 820 00 88 Retrofit antenna cable adapter
1  Velcro strip To hold GPS antenna in place


Parts Notes

Here is a eBay search tool that will find you a COMAND unit, although if you want to purchase a genuine warrantied unit from the UK, I suggest looking at 

If you want to install the antenna in the roof, as per factory fit, which you must do if you have infra-red reflective glass, then you will need

Antenna Pack  (with GPS) A251 820 02 75 (but see below).
Antenna Cable   A164 440 37 05

Installing those is difficult as you have to drop the roof liner.

MB don't list a part to just add a GPS antenna to the existing Antenna pack, and therefore the pack with all the antenna is rather expensive. I suspect the SLK antenna may be possible to insert in an existing antenna pack - it is part number A171 820 13 75


Installation consists of the following steps: -

  1. Remove old head unit
  2. Install GPS antenna
  3. Install COMAND
  4. Reassemble
  5. Have dealer Code COMAND and Cluster with Star DIagnosis

1) Remove old head unit

This is a quick guide to removing & re-installing the COMAND or Audio head unit in the ML (new, W164) or GL. This is a very simple process !

Firstly remove the whole panel below COMAND with the aircon and other buttons - this is done by opening the ash-tray, and putting 2 fingers below the panel on each side, pushing upward to release the latches and pulling hard. Here is a picture showing where you are pulling once the ashtray is open.

ML centre dashboard picture

The picture below shows one of the latches that your fingers are pushing upwards - there is one at each side

ML lower control panel latch

You then see two silver bars below the audio head unit - remove the 2 TORX screws, silde them downward, and then you can remove the head unit. Here is a picture with the screws removed and the locking bars moved downward.

ML comand locking bar picture

Install is reverse of removal !


2) Fit GPS antenna

Attach adapter cable to antenna, and using velcro fix it on the top of the plastic ledge above the COMAND unit. The hole (as shown in the picture below) should be facing towards the sky, and the velcro on the metal side below that you can not see here.

Mercedes GPS retrofit antenna picture

Note also that you should not remove the protective paper from the visible side of the antenna (which I did) as it leaves a sticky surface for sticking the aerial to the windscreen on the SL/CLK.

3) Re-assemble

Ensure the COMAND unit is pushed in well, with cables dropped below to ensure good airflow around the rear, slide up the latches and screw in the screws

Clip the panel with the aircon controls back in

4) Have MB dealer code unit and Cluster.

The dealer must code the AGW (which is in the COMAND on the ML/GL/R), specifically telling the system what is on the fibre optic bus (or if nothing is on it), and checking that the AGW flash software is up to date.

The dealer will have to inform the MB country headquarters that COMAND (option 527) has been added and the existing audio system removed from the vehicle and have them update the FDOK system at Mercedes in Germany. If your audio system was Audio-20 CD, that is option code 520. This may take a few days, so you may like to have them do this before you take the vehicle in, so thet can do all items together.

Only once the FDOK update is complete, the dealer must then re SCN code the instrument cluster so it knows that the vehicle has the navigation system.

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