Missing Hermes Communication Control Unit

[RayHandy]

Hi, last summer I purchased my first Mercedes - a 67 reg. C Class C200 Estate, petrol auto (S205), one owner, low mileage (23k), service history, fresh MOT. It was supplied by a small independent prestige cars dealer, 320 miles away. The car drives and performs well.
However, everytime I switch on, a message comes up - ‘SOS Inoperative’, and I assumed this must relate to a MB rescue service that would only have been available during the warranty period. On further investigation I found out that this message is controlled by the communications control unit which is located under the boot floor. On searching for this, I discovered that this unit has been removed, and the three wiring connections (1 white block connector, 1 pinky red connector, 1 green). It appears to have been forcibly removed, the plastic cradle frame is cracked, and the boot floor panel has cracked corners. The car dealer knows nothing off this, and of course is a long way away from me. So -
1) Any ideas why someone would remove this unit?
2) Is any damage being done by running the car without it?
3) Many S/H units are for sale for a C Class of this age but all with differing part numbers, and some with differing coloured connections. Could any S/H unit with correct coloured connection be fitted and the programmed by a MB Specialist?
4) I have searched a European website for a MB new part number for the actual model and year ( available for approx £600), but the images of this unit show differing coloured and shaped connections to those on my car.
Any guidance would be most appreciated.

 

[richard]

I'm pretty sure (but have not tried) that you can't use a used unit because it has an e-sim in it and that all gets linked into the Mercedes back-end database for online services (used to be called the DVB, Daimler vehicle backend). I.e I have only installed the odd new unit. It then needs configuring with online Xentry so it all registers and Mercedes know its your car its connected to. So you need a proper independent with supported online Xentry Diagnosis - or a mercedes dealer !

Also, there is little point installing the 3G version as 3G is being discontinued so need to look at your car's VIN to understand whether it is 3G or 4G and then modify if needed.

Now the bad news, it's that module that reports position back to Mercedes, so it is normally forceable removed on a vehicle that has been stolen at some point. So I'd consider doing your own full vehicle check on the car.

No problem running without it, but if you have a major crash the car will not automatically call the emergency services and you can't use the emergency button .... I don't know if that is something the insurance company may be upset about or not, I suspect it is not but dont have experience ...

Richard

 

[Petrol Pete]

Ouch ! Ray . The 'Now the bad news ' bit that Richard posted needs to be investigated. It appears that your unit was removed in a hurry .

 

[RayHandy]

Hi, thank you for the prompt reply and guidance.
I did organise an h.p.i. preliminary check prior to purchase and it came back all clear apart from having a private plate transfer earlier. It drives as new, is in good condition with no sign of any bodywork repairs, and the MOT and service history verify the low mileage. I did wonder if the comms control module had been removed because it was malfunctioning and throwing out fault messages on the dashboard etc.?
I will, however, for peace of mind have a more thorough provenance check carried out. Thanks again.

 

[Bobby Dazzler]

Hi, thank you for the prompt reply and guidance.
I did organise an h.p.i. preliminary check prior to purchase and it came back all clear apart from having a private plate transfer earlier. It drives as new, is in good condition with no sign of any bodywork repairs, and the MOT and service history verify the low mileage. I did wonder if the comms control module had been removed because it was malfunctioning and throwing out fault messages on the dashboard etc.?
I will, however, for peace of mind have a more thorough provenance check carried out. Thanks again.

I forget the details now but I remember there being a recall on the Hermes unit in some models. My wife thought she’d be getting a new handbag out of it

It might be worth checking whether your car had the recall as if it is still outstanding then it may be because it was missing at the time of the recall.

 

[markjay]

I know that the W205 had 3g modem when launched in 2014, and the facelift model launch in 2018 had the 4g modem, but I am not sure if your 2017 car would originally have the older 3g modem or the newer 4g modem.

As Richard said, no point in fitting the old 3g modem, so only go for a new modem if your car can have the 4g unit.

What you are also missing without the GSM modem is TomTom Live Traffic (which is a paid subscription) and any remote Mercedes me services.

 

[Djmickydoo]

Hi, last summer I purchased my first Mercedes - a 67 reg. C Class C200 Estate, petrol auto (S205), one owner, low mileage (23k), service history, fresh MOT. It was supplied by a small independent prestige cars dealer, 320 miles away. The car drives and performs well.
However, everytime I switch on, a message comes up - ‘SOS Inoperative’, and I assumed this must relate to a MB rescue service that would only have been available during the warranty period. On further investigation I found out that this message is controlled by the communications control unit which is located under the boot floor. On searching for this, I discovered that this unit has been removed, and the three wiring connections (1 white block connector, 1 pinky red connector, 1 green). It appears to have been forcibly removed, the plastic cradle frame is cracked, and the boot floor panel has cracked corners. The car dealer knows nothing off this, and of course is a long way away from me. So -
1) Any ideas why someone would remove this unit?
2) Is any damage being done by running the car without it?
3) Many S/H units are for sale for a C Class of this age but all with differing part numbers, and some with differing coloured connections. Could any S/H unit with correct coloured connection be fitted and the programmed by a MB Specialist?
4) I have searched a European website for a MB new part number for the actual model and year ( available for approx £600), but the images of this unit show differing coloured and shaped connections to those on my car.
Any guidance would be most appreciated.

Hi their. Just wondering how you got on with this. Did you manage to get a second hand unit fitted and working. I'm in a similar situation needing to replace the original one as it was stolen. Well the car was stolen and in the 4 hours they had it they removed the Hermes unit and in doing so chopped the green connector off and generally ripped the boot interior out. Obviously looking to disable any tracking of the vehicle. Instead of throwing all the interior parts in the boot they must have just left them by the road while they changed the number plates etc. Be very useful to hear from you if you managed to sort the problem out. I'm going to try a second hand unit but the Merc specialist I'm using can't guarantee it will work. I also need to get hold of the green connector !

 

[richard]

You will likely need to run a new cable from that to the front (its a high speed data cable, used for USB between head unit or hub and comms module).

We've worked out how to upgrade cars to 4G comms modules, so if you get stuffed come back to us and we'll work out how to fix it and give you 4G (but that needs a brand new module, but we have them) and other parts and some database updates at Mercedes etc etc etc

Richard

 

[Djmickydoo]

You will likely need to run a new cable from that to the front (its a high speed data cable, used for USB between head unit or hub and comms module).

We've worked out how to upgrade cars to 4G comms modules, so if you get stuffed come back to us and we'll work out how to fix it and give you 4G (but that needs a brand new module, but we have them) and other parts and some database updates at Mercedes etc etc etc

Richard

Hi Richard many thanks for your reply. I was hoping to buy a second hand unit to at least try. My intention is/was to get hold of one with the green connector still attached so it should be relatively simple to reconnect the wires. My car is a 2017 C220 amg line premium plus convertible diesel automatic. I think it would have the 4g capability but not really sure. The part number for the Hermes unit for my car is A2139003617. There are a fair few s/h units about but I don't know if my car has to be the exact same model that the S/H Hermes module came out of, it seems to be in quite a few different models. Many thanks Michael

 

[richard]

A213 900 36 17 is 3G module. It's a shielded data cable, so hard to repair. I've tried a 2nd hand module on something else and it didn't work - but that doesn't mean it wont work on a 205 cabriolet.

 

[Djmickydoo]

A213 900 36 17 is 3G module. It's a shielded data cable, so hard to repair. I've tried a 2nd hand module on something else and it didn't work - but that doesn't mean it wont work on a 205 cabriolet.

Thanks once again Richard for your advice. No doubt i will end up installing a new unit lol !

 

[RayHandy]

Hi, sorry to hear of your comms unit theft troubles. On Richard's advice I haven't tried to install a secondhand unit. After the comment about a the possible vehicle theft I paid for a more detailed history check, resulting in evidence confirming that the car had passed through a salvage auction as stolen/recovered with vandalism damage, including photographs showing the boot area trim ripped out. This auction took place 14 days prior to me purchasing the car, following an advert in Autotrader. Seemingly the C Class is the fourth most popular car to be stolen in the UK, even ahead of Range Rovers.
After talking to Citizens Advice, I intend to buy a new comms unit and have it fitted by a Mercedes Specialist, and then challenge the original deal for compensation to cover costs. However, I am struggling to find the exact part number and retail cost of the unit. I wonder if I gave out my Reg. No. and VIN number, is there anyone out there who could provide this information? Any help or guidance would be much appreciated. Thanks.

 

[Djmickydoo]

Hi, sorry to hear of your comms unit theft troubles. On Richard's advice I haven't tried to install a secondhand unit. After the comment about a the possible vehicle theft I paid for a more detailed history check, resulting in evidence confirming that the car had passed through a salvage auction as stolen/recovered with vandalism damage, including photographs showing the boot area trim ripped out. This auction took place 14 days prior to me purchasing the car, following an advert in Autotrader. Seemingly the C Class is the fourth most popular car to be stolen in the UK, even ahead of Range Rovers.
After talking to Citizens Advice, I intend to buy a new comms unit and have it fitted by a Mercedes Specialist, and then challenge the original deal for compensation to cover costs. However, I am struggling to find the exact part number and retail cost of the unit. I wonder if I gave out my Reg. No. and VIN number, is there anyone out there who could provide this information? Any help or guidance would be much appreciated. Thanks.

Hi Ray.Thanks for making contact. Blimey that must have been a shock when you discovered a bit more about the cars history. I hope you manage to get some compensation from the seller. I think the part number you need is A2139003617. Cost seems to vary but new from £450+vat and coding etc. As Richard said though it is 3g ! The colour coded connectors should match up to those in your wiring loom. It appears on mine only the green and purple ones are used and the bigger multi way grey one. No problem getting hold either s/h or new. My problem is they chopped the green plug off the wiring loom and I'm struggling to find another so I have to get that sorted out first. Also not having any joy finding a S/H boot interior so looks like I shall have to buy new for that too !! Thieves only had the car for about 4 hours. It was only the fact the tyre blew out near Gatwick I got it back at all. Good luck sorting yours out. Regards Mike

 

[SpikyMikey]

Hi Ray.Thanks for making contact. Blimey that must have been a shock when you discovered a bit more about the cars history. I hope you manage to get some compensation from the seller. I think the part number you need is A2139003617. Cost seems to vary but new from £450+vat and coding etc. As Richard said though it is 3g ! The colour coded connectors should match up to those in your wiring loom. It appears on mine only the green and purple ones are used and the bigger multi way grey one. No problem getting hold either s/h or new. My problem is they chopped the green plug off the wiring loom and I'm struggling to find another so I have to get that sorted out first. Also not having any joy finding a S/H boot interior so looks like I shall have to buy new for that too !! Thieves only had the car for about 4 hours. It was only the fact the tyre blew out near Gatwick I got it back at all. Good luck sorting yours out. Regards Mike

I know absolutely zilch about the MB Hermes unit, but part of my work remit often involves tracking down obscure fasteners. You may be able to source your missing HSD plug from here:
Co-Star - Specialists in Engineering Consumables & Communications Equipment
I don't know which 'flavour' of plug you need though - maybe Richard can help there. I'd just endorse what he says; splicing back into shielded cables is not the best solution.

 

[SpikyMikey]

I know absolutely zilch about the MB Hermes unit, but part of my work remit often involves tracking down obscure fasteners. You may be able to source your missing HSD plug from here:
Co-Star - Specialists in Engineering Consumables & Communications Equipment
I don't know which 'flavour' of plug you need though - maybe Richard can help there. I'd just endorse what he says; splicing back into shielded cables is not the best solution.

Edit: "fasteners"should read "connectors"

 

[Djmickydoo]

Edit: "fasteners"should read "connectors"

Thanks for that SpikyMikey. I did actually come across that company in my search but couldn't really work out which connector is the correct one. I will work it out though lol. When they cut the connector they cut it right by the Hermes unit so their is some slack to attach a new one. Just have to make sure it's reconnected properly.

 

[SpikyMikey]

Thanks for that SpikyMikey. I did actually come across that company in my search but couldn't really work out which connector is the correct one. I will work it out though lol. When they cut the connector they cut it right by the Hermes unit so their is some slack to attach a new one. Just have to make sure it's reconnected properly.

Someone with access to the wiring diagrams should be able to help you with the pin outs.
Looking at HSD connectors generally, it appears the critical thing is to get the correct keyway configuration to match your unit.
This may help.... if you skip through the pdf to page 18, it gives an end on view showing the various layouts. Hopefully it should help getting you closer to matching what you need.
https://www.rosenberger.com/fileadm...ial_Data_Connectors/AUTO_HSD_Catalog_2020.pdf

 

[richard]

Hi, sorry to hear of your comms unit theft troubles. On Richard's advice I haven't tried to install a secondhand unit. After the comment about a the possible vehicle theft I paid for a more detailed history check, resulting in evidence confirming that the car had passed through a salvage auction as stolen/recovered with vandalism damage, including photographs showing the boot area trim ripped out. This auction took place 14 days prior to me purchasing the car, following an advert in Autotrader. Seemingly the C Class is the fourth most popular car to be stolen in the UK, even ahead of Range Rovers.
After talking to Citizens Advice, I intend to buy a new comms unit and have it fitted by a Mercedes Specialist, and then challenge the original deal for compensation to cover costs. However, I am struggling to find the exact part number and retail cost of the unit. I wonder if I gave out my Reg. No. and VIN number, is there anyone out there who could provide this information? Any help or guidance would be much appreciated. Thanks.

They are about £500 inc VAT RRP. Send me a PM I can do you one a bit cheaper.