MBStream

Thanks for the reply Dutch!

My VIN is 4JGDA5HB7DA216263

Can you confirm that MB actually uses a different SAM if you have a tow setup?
IE - If I was to pay MB the $2500 they want for the hitch install, would they put a new SAM in the car or just update the one I have?

Thanks for all the help!

James Courtney

I *THINK* I read somewhere that the towing SAM isn't included or programmed properly unless you have the trailering package (Code 550). Dutch is right, dealers or service centers can see if you had the factory option by looking up your VIN. I also concur that 4500 LB. is a lot to pull without it's own brakes and I'd be very reluctant to do anything but a short trip around town with that. That's almost the weight of the tow vehicle. I think if I didn't have the factory towing option I'd speak with my dealer and see what they could retrofit and at what price. It'll undoubtedly be a 4 digit number. If they can add the draw-bar and basic wiring harness without undue difficulty and cost then you could potentially use a wireless controller and avoid more serious electrical surgery:

http://www.etrailer.com/Brake-Contro...sha/90250.html

If you own the Airstream this might be a good consideration. I borrow trailers so for me it's not a great option.

DUTCH

Unfortunately, you do not have the 550 Towing Package and your rear SAM is not the one (A.246.900.55.01) for the towing package. Sorry.

Since you were not nervous about posting your VIN, I'll post your Vehicle Data Card here, too. If you don't want that posted here, let me know; and I''ll delete it.

MBStream

Dutch

Thank you very much for looking that up.

Do you know if the rear SAM can be purchased to replace mine? From the reading I have done on the site it appears that this (and the wiring) are the primary parts to the towing package.

It does not appear that their is any special transmission cooling, etc. that is part of the towing package.

Thanks
Eric

waejae

I am looking to replace the factory 7 way plug with a magnetic one.

Does anybody know if there is a male side to the female connection for the back of the 7 way.

I do not want to cut the factory connector off.

http://ezconnector.com

kingair350

I realize this is an old thread, but does anyone know which of the four wires goes into the one pin that is different from the other 3, part # A046 545 40 28. The TB does not say

skw

Bringing this thread back. Any updated info on where the harness may now be located? Looked and looked this afternoon and couldn't find it anywhere behind the carpet nor near the obd2 wiring. Wires into the obd2 ports had the masking tape on them but no green harness attached. See pic below. Car is a '16GLE. I definitely have the factory hitch and 7pin connector in the rear. Confirmed on the original window sticker option 550. I bought the Tekonsha P3 and planned on towing a travel trailer 3 days from now. Any help is appreciated. Will also call the dealer when they open in the morning.

skw

See post #13. The only wire size that is different is the one for the brake light circuit.

Diabolis

This likely won't help you, but I was in exactly the same situation a couple of months ago trying to figure out how to connect a PBC to my 2015 ML350 BlueTec with the factory towing package for a ~4700 lb trailer (loaded w/ race car, tools and spares). Rather than go through the hassle of trying to wire a PBC, I ended up going with the Tekonsha Prodigy RF wireless and it's every bit as good as any wired proportional brake controller on any other tow vehicles. It simply plugs in the lighter socket when you're towing. No need to look for plugs that may or may not be there, make holes and molest the ML / GLE wiring harness in any way.

skw

I didn't go w/ the RF unit because I had read that you have to pair it on another vehicle 1st before using it on our cars, which i don't have access to. I stopped by the dealer yesterday and long story short, they found it under the carpet behind the gas pedal. Didn't have to cut or splice into any of the factory wiring. I used 4 of the larger sized pins in the pdf a couple of posts up right onto the ends of the wires from the P3's harness and made my own plug as was illustrated. Also used a 30A self resetting breaker on the black power wire. It's long enough to reach into the cubby by the ash tray and the wires can be tucked back under the panel below the steering wheel when not in use.

Diabolis

Good to know the connector is still there in the GLE and that the vehicle doesn't require any surgery.

Yes, I have heard about the initial pairing issue with the Prodigy RF and some european SUVs, but it was all already done by the trailer shop before I picked up the trailer. And, I recall reading somewhere that in order for the initial pairing to work on MBs (and likely other affected vehicles), one of the pins in the electrical connector needs to be disconnected or isolated with some electrical tape before the pairing. It's a one-time thing and once the remote and trailer module are initially paired, they stay connected.

Good luck - and please post in the other thread how the 2.1L turbo diesel fares when hauling a 6000 lb trailer.

skw

I have the V6 gas engine w/ 4Matic, rated to tow 7200lbs. I think the 300d 2.1L diesel drops down to 6600lbs. The trailer I rented was a 30' at 6300lbs and I had a w/d hitch as well. All 3 tanks empty as I was going to a full hook up site. To be honest, it was taxing and I was glad it was a short ride. No issues w/ swaying on the highway but just felt like too much trailer behind me, if that makes sense. Uphill most of the way and 90+ temp didn't help neither. Next time would probably go with something around 27' and a bit lighter.

Diabolis

Right... for some reason I thought you were going to tow with a 2.1 diesel, which IMHO would have been outright anaemic. Sorry - my bad.

Even with the bigger motor, a 6300 lb trailer can be a handful. Last year I ended up towing an empty 30' toy hauler for a friend (except for equipment - I am guessing it was around 5,500 lbs) for maybe 150 miles and it was a harrowing experience. I barely feel comfortable with the 15' Trailex car hauler on mine.

SCHUTZEE

"I barely feel comfortable with the 15' Trailex car hauler on mine."


I'm considering towing my Cayman to track events on a Trailex. Do you think I'd be better off looking for a GL rather than as ML? I will probably go diesel either way.

skw

If new, the GLS has the 6 cylinder diesel vs the GLE w/ the 4 cylinder. You mention ML, so I'm guessing used whereby they have the same engine. GL has a 121" wheelbase vs the ML w/ a 114" wheelbase. Might feel a lil more stable w/ the GL.

SCHUTZEE

Yes, I would go with a CPO vehicle either way.

Diabolis

Regarding my comfort level when towing, I was only referring to having a huge and realtively heavy trailer behind me when driving uphill or downhill on twisty 2-lane roads at 3 AM and having to swerve to avoid a deer. The engine power and hauling capability are more than sufficient, and there are no stability issues whatsoever with the ML. I've never had as much as a hint of instability with the car trailer even when moving at speeds that would get you in serious trouble with the local constabulary on public highways. The only thing that will take a serious hit is your fuel consumption rate.

In Canada the ML350 BlueTec was manufactured and sold throughout 2015 (I bought mine new at the end of November 2015), and now continues as the GLE350d on the same W166 platform, with the same 3L V6 turbodiesel engine. I briefly considered the GL (now GLS) but seeing as it has the same motor and I didn't need the extra space, it was an easy decision. The GL(S) just weighs more, so all other things being equal, if you don't need the extra room I can't see how it would have any advantages over the ML/GLE for towing a car.

cazdazoz

I called MB Australia this week to see if there is a genuine MB electric brake controller and they said YES. It was going to cost $400 plus installation. When I asked for a picture of the unit they said they don't have one! For that price I would want something totally integrated to the dash or something like RedArc Tow Pro Elite.

Does anyone have a picture of this controller? Or recommend a unit that will work well on the GL.

Thanks

darren

mikapen

Get the Prodigy RF. If you have a problem pairing, call Tekonsha - an Engineer will answer and will walk you through the process. Most people have no problem - we didn't.
If you only have one car and need another to complete the pairing, call a friend with a car.
The Tekonsha engineer I talked to said the RF is the highest performing unit they make.

We strap ours to the Driver's grab handle next to the console, which is a much more convenient location than reaching all the way to the dash if you need to quickly apply some trailer brake.

mikapen

Our '10 Bluetec ML is VERY stable pulling our 27', 6000# RV. I wouldn't pull that much without a Weight Distributing hitch and external sway control, though.

Wheelbase is not a big factor in stability - it's the rear overhang (axle to ball distance) to wheelbase ratio that is the operative measurement here. The ratio may be more favorable on the ML (I'd have to check) but it's not significant here.

Setup and loading (10 - 15% of trailer weight on the tongue) are the most important.

With our setup, handling is surprisingly agile, and emergency stop-and-avoid situations are very much in control. More than a half ton pickup in my opinion, with their WWII suspensions, undersized brakes and floppy frame rails.

We certainly don't hold up traffic on the 2-lane twisties!

sstrohm

I just bought a 2011 MB ML350 BlueTec because it can tow 7200 lbs. The vehicle has an after market Curt hitch that will tow 3500 lbs. No wire harness, but I will get that installed by a dealer. Looks like I'll go with the Prodigy RF, but you would thing that MB would make this modular, just like American truck manufacturers. Who makes a 7200 lb tow vehicle without a factory hitch and harness? Frustrating!

Diabolis

The ML is first and foremost a luxury SUV, and while it can be used as a tow mule, 99 out of 100 people that have one will never tow anything with it. This is the reason why MB doesn't put a tow hitch on every single one, just like any other luxury SUV form Audi, BMW or Land Rover. The vast majority of owners simply use it as a daily driver.

If you got one with a factory tow package, in addition to the hitch you get the harness with a 7-pin plug, subframe reinforcements, SAM, additional transmission cooling capacity and some ECU programming that detects when a trailer is connected and alters transmission shift points and various stability programs. If you intended to use the ML for towing, why didn't you get one with the tow package preinstalled from the factory?

mikapen

I would be very careful of the Curt hitch, and I'm not sure I would approach the "limit" on the hitch. It is probably not mounted to a reinforced place on the chassis, - most likely just screwed into sheet metal. That's recipe for failure and potential tragedy.

The M-B factory hitch, on the other hand, includes interior chassis reinforcement, reinforced pickup points, and a rear SAM (signal acquisition module) that provides tow-haul mode, trailer sway and light monitoring, plus more. (The increases trans and engine cooling is included in all 4Matic models even if you don't get the tow package.) That's where you get the 7200# capacity.

The factory hitch is only $650 if ordered on the car - but @$2000 if added by the Dealer. It's the same unit, but the rear of the car must be disassembled to mount the chassis reinforcements, and the rear SAM must be reprogrammed to recognize the trailer.
Even at the price of @$2k, it's worth it for the massive towing abilities of the ML Diesel. I would consider selling the Curt hitch and stepping up to the real factory hitch if you are going to do any real hauling.

We tow our 27' RV, 6,000 lbs, and it's a great match - pulling, braking, emergency maneuvers, mileage. The hitch setup, the electronics, and the brakes are superior to most half ton pickups. We use a Weight Distributing Hitch - something that is recommended even on 3/4 T pickups for safety and handling.

Jethro4640

Guess this thread just will never die..

So, 2014 ML350 BlueTech with factory tow package. Found the harness right where it should be BUT there is 0 power going to it. I've ran the multimeter from ground across all 3 other wires to include the Red/blue that should be the BrakeController's power wire, yet 0VDC. Any ideas?

(Vehicle was on, pressed the brake a few times, verified the multimeter against the battery under the hood)

Diabolis

Is the 30A fuse inserted? Do you have power at the fuse block?