Retrofit DAB/DAB+ CLS C218

[mprivate]

Hi everyone,

I have a 2017 CLS 63 S (C218 facelift) with COMAND NTG5.1 and Bang & Olufsen (MOST). My car did not come with option DAB / SA 537 from the factory, and I'm looking to retrofit it as close to OEM as possible (no USB dongles or FM injectors).

Most retrofit guides I've found online are for NTG4/4.5, so I'm trying to confirm what's required for NTG5.1 on the facelift C218, and from what I understand, the OEM-style retrofit should involve:

* DAB/DAB+ tuner module (MOST device, likely mounted in the trunk near the B&O amp)
* DAB-capable antenna amplifier/antenna path (Band III)
* Coax from antenna amp to tuner
* Inserting the tuner into the MOST ring
* Coding/activation afterwards (I can arrange coding, but I need help with hardware installation)

Important: I'm good with mechanical work (engine, drivetrain, etc.), but I have minimal experience with wiring/electrical, and I don't want to break the MOST ring or damage anything.

For reference, here is a VIN from a facelift CLS 400 with factory DAB that I'm using to compare wiring/equipment:
WDD2189611A124574

Questions:

* Has anyone retrofitted OEM DAB/DAB+ to an NTG5.1 facelift C218 (especially with B&O)?
* Which DAB tuner part number(s) work reliably with NTG5.1 in the C218?
* Does the retrofit require changing the antenna amplifier or even rear glass, or is it enough to add the correct antenna amp + coax?
* Where exactly is the cleanest place to insert the module into the MOST ring on the C218 with B&O?
* Any tips on avoiding common mistakes (fuse, MOST loop, coding order, etc.)?

I'm happy to pay for information or close assistance, if possible.

Thanks in advance.

 

[mprivate]

Here's a short update based on my research on what needs to be ordered, replaced, and done afterward.

I've ordered the following parts:

A2229005117 – Digital Radio Control Unit (DAB Tuner, Digital Audio ECE)
A2129053406 – Antenna amplifier
12V Y MOST fiber optic cable (1× female, 2× male)
Fakra cable, male-to-male, 4 meters

Back in 2023, I asked Mercedes about the retrofit cost. They quoted around €4,200, which included replacing the rear windshield and some additional work, so I declined. This year, I decided to tackle the retrofit myself.

The general plan is as follows:

The DAB tuner box will be installed on the left side of the trunk and secured with brackets. I'll order the brackets once all parts arrive and I've confirmed that everything works correctly. The MOST connector will be removed from the Bang & Olufsen amplifier and connected to the Y-shaped MOST cable. One output will go back to the amplifier, and the second output will go to the DAB tuner box.

From what I understand, the tuner box receives its power directly via the MOST connection, since it has no other connectors apart from the MOST input and the antenna input. The antenna amplifier will also be installed in the trunk. I still need to determine the exact mounting location. It will be connected to the DAB tuner using the Fakra cable. This is just a high-level summary for now. I'll post pictures and a more detailed update next week once I start the installation.

As for coding, only variant coding should be required on HU55 (head unit) and possibly CGW_212 and IC_204. I'm not 100% sure about the last two yet, but I'll verify that during the process. There will probably be some trial and error along the way, but if I don't try, I'll never know.