metkhoo

Hi,
I have a M-350 Right hand drive without a tow and wanted to install an electric towbar myself
I think I know the rear Tow Bar Control module is
A246 900 55 01
And the harness to go to the SAM from this module is:
A166 540 44 10
I also have options 876 INTERIOR LIGHT ASSEMBLY and 234 BLIND SPOT ASSIST
I have a copy of the retrofit instructions which clearly say that the driver door control module should be replaced that has support for the tow bar switch.

However, I can't work out which module it needs to be replaced WITH

I think it is
A166 900 44 02
As it seems to support my options AND the trailer coupling option 550

Any guidance gratefully received
Many thanks

/Marcus

Zuffen

I fitted a tow bar to my ML350 and didn't need any additional items over what was supplied.

My bar has a removable ball but isn't electric as I figure I can get on my knee to remove and replace it.

My bar was manufactured by HAK Systems and took a serious 8 hours to fit by myself.

I build cars as a hobby so I'm very mechanically competent.

metkhoo

Hi Zuffen
Did you have to take out the Ad-Blue tank to access the nuts on the driver side?
From my instructions, one needs to take off the Rear Wheel fender and then take out the Ad-Blue tank then take off the rear bumper and lower the silencer and heat shield.
Also to take out the rear wheel carpet in order to access the longditudinal members.
Is that what you needed to do?
/Marcus

Zuffen

Basically yes that was the order of operation.

Only difference is I have a gas model so no S Blu tank.

The rear bumper was a total ***** to get off but finally managed it.

When refitting the rear bumper (if working by yourself as I did) use masking tape on the top points of the bumper and tape the sides of the body as it would be easy to scratch one or the other.

Hameed_W166

metkhoo & Zuffen , Hi
I think the retrofit you made is awesome and i am seriously thinking of adding the electric trailer hitch to my ML350 model 2013 as I own a boat.
I appreciate your help if you can share with me any instruction as well as the component required. I made a quick research before and I couldn't gather everything i need? as far as I know I will need:
- The trailer hitch
- Module
- Harness
- Switch buttons (for front & Trunk)

I am a competent mechanic and I am willing to install it myself.
Regards

metkhoo

Just to be clear, I have not actual put it on yet but am collecting the parts. D
o you have option 915 = 93 litre fuel tank? According to my instructions that is needed too
These are the parts that I will collect:
Note that you must use the correct and brand new nuts and bolts when doing this work as they are all specifically selected by Mercedes to do their job and all rated for the tow bar

You need:

1. A166 310 01 04 Electric Tow Bar mechanism
2. A166 440 70 13 Hitch harness - from trailer recognition module to hitch plug (This harness links to the control module - this will normally come with a tow bar itself)
3. A166 310 01 18 1 long member left
4. A166 310 02 18 1 long member right
5. A166 315 00 65 Bumper foam
6. A246 900 55 01 Tow control unit
7. A166 540 44 10 Main harness from SAM to Tow controller unit
8. A166 905 17 00 Rear Door switch
9. A166 905 10 51 Driver Door switch + wiring clutch to go to the driver door module.
10. n0000 0000 3749 qty 2 screw
11. n0000 0000 6409 qty 4 bolt
12. n0000 0000 6964 qty 4 bolt
13. n0000 0000 3275 qty 8 nut
14. A166 470 01 81 not sure what quantity one or two = Ad Blu bracket

Also maybe you will need a new driver door control module - I have not worked that out yet.


Lastly you need access to STAR C4 to program it all up

The installation is not for the faint hearted. I will post separately

Best regards
/Marcus

Zuffen

I purchased my bar as akit that had everything I needed.

The kit came from P.P.H.U Euro Auto in Warsaw Poland.

Ordered it online and it arrived at my front door.

Much easier than chasing around trying to source arts separately.

I only had 1 module to install plus hook up to the fusebox under the rear seat and hook into the o/s B pillar junction box on a right hand drive vehicle.

My tow ball is removed manually but I don't do it too often so that doesn't bother me.

Hameed_W166

Yes, I think ordering everything as a kit is much better than collecting every item individually. I made a quick search and found this used tow bar in Poland too. by looking at the photo I see pretty much everything Marcus stated apart from the switches and bolts

Zuffen

That;s a different bar to mine.

My cross piece is rectangular not round.

Hameed_W166

this is how this tow bar looks like when installed

metkhoo

That’s the one I have too.
from a hardware perspective you will also need the Towing ECU (which I may have spotted taped to the right longditudinal member, not sure) the door ECU (maybe), the switch for the rear door, the switch for the driver door, a cable harness between SAM and tow ECU, the tow bar bumper foam and you should REALLY REALLY get new nuts and bolts from Mercedes.

by the way - it is really heavy !!!

/Marcus

Hameed_W166

Indeed, the module is taped on the right side, I will definitely get a new bolts for sure. Now i need to think the best way to ship it to my country as it is heavy as you said i will eliminate air shipping as it is costy

nikola19

Hello friends! Is there anyone who done with retrofiting an oem tow?