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There have been quite a number of towing thread in this forum. Can you try the search feature? The threads are well populated with information.
Typically a "towing package" includes the capability to control trailer lights, and in most cases electric trailer brakes. Plus the hitch of course.
Regarding tow rating, this section (V167) and the W166 section has dozens, or more, posts on this question. You can tow 7700 lbs, using proper equipment. This could include a weight distribution hitch and electric brakes. 7700 lbs is "all in" meaning trailer + full propane tanks + dishes + linens + television + etc. You get the point. Dry weight of the trailer is meaningless. Laden trailer weight including its contents is the only thing that matters.
Ignore comments on the "80% rule". No such rule exists. Tow up to the rated capacity of the manufacturer with confidence.
@BACnMercedes That's what the large black thing to the left of the gas pedal is for. It's connected to all four wheels, and to the trailer axles when equipped with an electric brake controller. Do you agree?
Haha. Yes. Step on the brake. But I bet when you are towing a 7700lb trailer and step on the brake for an emergency stop, its going to be scary. Or at 55 on the interstate towing 7700lbs when a large truck passes you, you might hear the rumble strips as the vehicle gets squirelly and you pucker up!
When the trailer is heavier than the towing vehicle extra care is in order, IMO. I agree with both Chassis & BAC.... The trailer brakes will help but the GLE brakes will dominate since they are much more effective. Also the shorter wheelbase of the GLE vs a truck can be a factor. Tow up to max, no problem, but try to avoid a situation that requires full braking by keeping a little extra distance from the vehicle ahead. If you are new to towing error on the side of being conservative until you get used to towing and how the vehicle reacts. My first trip I bent an axel because I was forced to make a sharp turn as a car sped into an entry spot...so I bumped over a curb with a heavy boat. You need a little extra space to make a turn since the trailer doesn’t follow the same track.
The past couple of comments on braking can be summed up with the knowledge that towing a trailer is not the same as driving to the drug store for shaving cream.
You need to know what you are doing.
If you don’t know what your are doing, or have less than 98% confidence in your abilities, don’t tow a trailer.
The towing package also includes the 7 pin electrical connector to the trailer, prewired brake controller plug under the drivers side dash, and some integrated software to help control sway, identify if a trailer is connected to disable some normal features like blind spot detection and confirm trailer lights are all operating. The tow weight restrictions are maximum numbers so tow up to those limits and do not forget about tongue weights also. Tongue weights should be 10-15 % of the trailer weight to avoid trailer sway. Best to check all these on a truck scale to confirm the maximums are not exceeded and also confirm individual axle weights are not exceeded. A weight distribution hitch is recommended and anti-sway devices for larger trailers. You will need a brake controller for anything over 3000 lbs approximately and I recommend a proportional brake controller. I use a Tekonsha Prodigy 2 and you can plug connect directly to the GLE prewire under the dash. You will also need some tow mirrors if you have a wider trailer. The GLE 450 has better brakes than a lot of 1/2 ton pick ups and is a very capable tow vehicle.
The past couple of comments on braking can be summed up with the knowledge that towing a trailer is not the same as driving to the drug store for shaving cream.
You need to know what you are doing.
If you don’t know what your are doing, or have less than 98% confidence in your abilities, don’t tow a trailer.
Absolutely correct! And if you regularly tow at/near 100% capacity of the vehicle, you might need a bigger tow vehicle.
At which time you will have better brake performance than all but 1 ton plus trucks.
THEN, if you need to execute an avoidance maneuver while braking, there is not a pickup truck out there that will give you the control that a GLE will provide.
Setup, WDH adjustment and loading are important. Watch your "payload" and axle ratings, posted on the Drivers Door post for those numbers. Payload decreases as you have more equipment.
I’ll just quit expressing a point. To the original OP @Crispin tow as much as the vehicle is rated at wherever, whenever and however you want. Good luck!
On Brake Controller - use a wireless it's slick.. Yes, Mercedes engineers great tow features but intentionally does not promote them so not to increase potential liability..
One "gap" in the factory towing package - especially if you have Driver's Assistance - is mounting a hitch bike rate... backing up with a bike rack without a electrical hookup - a DA equipped car often senses the bike rack as a rear-crossing-pedestrian !
We use a Tekonsha Prodigy RF, wireless brake controller. It's great. Before I purchased, I talked to Tekonsha engineers, who told me it was the most advanced controller they provided. Plus, they said, since the inertial sensors are on the trailer, the signal better approximates the forces acting on the trailer (of course!).
The towing package also includes the 7 pin electrical connector to the trailer, prewired brake controller plug under the drivers side dash, and some integrated software to help control sway, identify if a trailer is connected to disable some normal features like blind spot detection and confirm trailer lights are all operating. The tow weight restrictions are maximum numbers so tow up to those limits and do not forget about tongue weights also. Tongue weights should be 10-15 % of the trailer weight to avoid trailer sway. Best to check all these on a truck scale to confirm the maximums are not exceeded and also confirm individual axle weights are not exceeded. A weight distribution hitch is recommended and anti-sway devices for larger trailers. You will need a brake controller for anything over 3000 lbs approximately and I recommend a proportional brake controller. I use a Tekonsha Prodigy 2 and you can plug connect directly to the GLE prewire under the dash. You will also need some tow mirrors if you have a wider trailer. The GLE 450 has better brakes than a lot of 1/2 ton pick ups and is a very capable tow vehicle.
Any chance you have a pic of the connector under the dash? I’m about to go connector hunting....
Any chance you have a pic of the connector under the dash? I’m about to go connector hunting....
Its been a while but i think it was up near the edge of the carpet. Look for the yellow red black and green wires with the green connector. You must have the trailer hitch package for this to be present. The plug was tucked in above and I pulled it down
Last edited by marchgroupinc; 12-06-2020 at 05:07 PM.
Reason: new additional info.
Its been a while but i think it was up near the edge of the carpet. Look for the yellow red black and green wires with the green connector. You must have the trailer hitch package for this to be present. The plug was tucked in above and I pulled it down
ok thanks so you had to partially drop the dash trim to get to it
from above?
Its been a while but i think it was up near the edge of the carpet. Look for the yellow red black and green wires with the green connector. You must have the trailer hitch package for this to be present. The plug was tucked in above and I pulled it down
What brake controller did you install and did it come with a plug that fit the green MB plug in your photo? I'm shopping for one right now and haven't found one yet with a plug that looks like it would fit this green plug. Maybe there are adapters?
I used the Tekonsha Prodigy P2 controller. Their model listing for wiring harness is not complete but as far as I know one plug for any late model Mercedes works. You don't show what country you are from but here is the Amazon one listed in Canada which I did not bother with, I just cut the plug off and wired it directly to Prodigy wiring harness.
I used the Tekonsha Prodigy P2 controller. Their model listing for wiring harness is not complete but as far as I know one plug for any late model Mercedes works. You don't show what country you are from but here is the Amazon one listed in Canada which I did not bother with, I just cut the plug off and wired it directly to Prodigy wiring harness.
Thanks. I've had my eye on that controller and with your clue, found the adaptor on Amazon. Now just need a new GLE to install it on, but that's a whole different story.
Here is the M-B factory bulletin for a W166 under dash trailer plug. I think it's the same as a V167 but you ought to check wire colors.
I ordered the parts through M-B parts. Then I added some wire loom wraps from AutoZone to keep things tidy.
I used this plug-in with a Tekonsha P3 at first, but didn't like the rather remote placement of the manual controller lever, so switched to a Tekonsha RF. Before changing, I talked to a Tekonsha engineer, who said the RF was their best controller. I agree - it actually works better, especially in low-speed maneuvers, like stopping for fuel.
Here is the M-B factory bulletin for a W166 under dash trailer plug. I think it's the same as a V167 but you ought to check wire colors.
I ordered the parts through M-B parts. Then I added some wire loom wraps from AutoZone to keep things tidy.
I used this plug-in with a Tekonsha P3 at first, but didn't like the rather remote placement of the manual controller lever, so switched to a Tekonsha RF. Before changing, I talked to a Tekonsha engineer, who said the RF was their best controller. I agree - it actually works better, especially in low-speed maneuvers, like stopping for fuel.
Good info - we have a 2021 GLS 450 not sure if this is a W166 or V167, don’t understand the difference to be honest. We have the tow package.
we bought the Curt wireless brake controller. The factory 7 pin plug is oriented at an approx 45 degree to the ground. The curt wireless unit is around 8 inches in length. So when it’s plugged into car it’s awfully close to the ground.....well somehow it hit something while driving/pulling our travel trailer. Torn it up a little bit....now trailer brakes are lock up and not getting 12 volts to some of the car pins on the connector.
Based on this not sure if I’m going back with a wireless system or not.
wonder if there is a fuse somewhere on the car for the trailer harness wiring.
Last edited by Collins350; 12-13-2020 at 09:04 PM.